I mean that's a super broad question to answer simply because we don't know. Since wood rots in almost every climate and circumstance produced by nature, almost all of it has and the only way we could know the potential is if it hadn't, and if all the wood didn't rot you wouldn't be asking this question because nothing would of been lost. So it's a bit of a paradox.

Besides that I dont think it's any great leap too assume that we have lost a lot. Less so I'm the field of smaller objects because they gave be placed into more preservative conditions than a larger wooden structures. For example we have preserved spear shafts like the the Lendbreen spear found in Norway, which is a spear from the viking era with a remarkablely preserved shaft which survived by being frozen in ice and recovered before it thawed out and was exposed, but a repeating phenomenon with something like a house, would be near impossible. We see this again and again with smaller objects being preserved in ice, and finds recovered by groups such as Secrets of the Ice are able to recover every day items of wood such as snow shoes, arrow shafts, saddle parts, and more.

So while we still lack quite a bit of information on smaller objects in or near climates which can work to preserve, we lack the most information in the fields of watercraft and architecture. Architecture is a bit easier to trace since when wood rots underground it will leave a different color soil which can be seen quite easily with the trained naked eye. This allows us to identify structures which were supported by wooden steaks driven into the ground such as Anglo Saxon and Neolithic British dwellings, such as reconstructed by West Stow Mueseum. (https://en.m.wikipedia.org/wiki/West_Stow_Anglo-Saxon_Village) So most of our information on architecture is only preserved on soil evidence like this or period depictions, which in many cases are also few and far between.

Lastly the hardest to preserve finds of wood are probably boats. It is likely that you know wood rots in water quite well, and boats are in it quite a bit so often our only finds of boats are when they are buried or parts of it are buried under, near, or away from water. So leading off of that we do have the occasional find from periods such as the Osberg Ship which was buried ceremonially in a funeral or the Utrecht Roman Barge which was used as a road support and was covered in silt as a result. We do have some finds like this from here and there but since boats aren't meant for land, they are all together pretty rare. When we do find one such as this (https://www-cnn-com.cdn.ampproject.org/v/s/www.cnn.com/travel/amp/roman-shipwreck-kefalonia-fiskardo/index.html?amp_js_v=a6&amp_gsa=1&usqp=mq331AQHKAFQArABIA%3D%3D#aoh=16229457688034&referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.cnn.com%2Ftravel%2Farticle%2Froman-shipwreck-kefalonia-fiskardo%2Findex.html) Roman cargo ship in the medditeranian or the Madrague de Giens, we may find a few scraps but the identifying feature is the cargo and shape. Often times cargo was transported in pottery due too its convenience, and since pottery is just earth stuck in fire it doesn't really rot so if it is in a relatively peaceful climate like hundreds of feet below the surface or sitting in a calm patch of water it won't crumble to be dispersed by tides. So in short we probably have the least info on boats just due too a lack of archeological evidence, both from difficult preservation and less human exposure and thus less chance of discovery, as well as many period works not taking time to detail intricacies of ships since most artists weren't sailors at the time.

Lastly any things that may of been preserved by wood. Now just carving things into boards hasn't been immensely popular as a form of sharing knowledge since its easier to write than carve and wood is hard to transport, store, and read. It can have bumps and knots and is hard to turn into planks so most cultures simply found better alternatives. Some cultures like China and Japan used early forms of paper, the middle east, Africa, Middle East, and Europe would of used parchment before exposure too paper. Some cultures used paper like alternatives such as Egypt's papyrus scrolls, other cultures such as Sumerians used clay tablets. But there were some uses of wood in writing. An archeological find I am quite fond of is Onfim's notes in Novgorod. In short it was a 6 or 7 year old boy who took school notes by carving it into sheets of birch bark, with these notes he also doodled, practiced letters, drew scenes of knights, monsters, battle, etc but that's besides the point. These along with other birch bark notes were found in a ditch outside of the city and had been preserved by silt. We also see things like this with certain North American Native tribes using birch bark to create geometric shapes and and art, but this seems like a more limited practice on an international scale due to lack of widespread used since there are better materials which fully literate people who were taught to write could more easily afford. Now as for wood carvings they would of been more decorative or symbolic rather than detailing actual information given it takes a long time to carve on wood, it is delicate work, and near impossible to transport.

Hope that answers your question.