Short answer: no.

Long answer:

Let’s talk about why not.

Hops

Hops are an excellent preservative in that they make it hard for bacteria to grow while not inhibiting the yeast that you need to make alcohol too much. While hops were used pretty early on in the Middle Ages (the first documented case of their use is in 822), these early hops were generally (very weak) wild hops and it took quite a bit longer for the cultivation of hops to become widespread. It started in northern Germany in the 11-1200’s and spread from there via Hansa trading ports and became popular in the low countries, but it wasn’t until 1362/3 when hopped beer started to be imported into England and it took even longer for it to become widespread. For example, if you read Shakespeare, you can hear his characters complaining about hopped beer and talking about how much they prefer unhopped ale centuries later.

Without hops it’s much harder to export beer out of the local area, as without a reliable preservative you could end up with spoiled ale. Also unhopped ale was generally not boiled which also didn’t help with its shelf life. It was only with the rise of hopped beer that beer became a common trading commodity and soon casks of ale were being traded far and wide. This allowed people to have a greater variety of beer.

Casks

This beer was generally transported in wooden casks and could generally still be drinkable quite a while later. In fact, in later centuries IPA was often aged in large vats for around a year before it was even shipped to India. These vats were often enormous, so big that people died in a huge porter flood when one of these vats burst. This meant that you could store casks of ale and still serve them quite a bit later.

However, as soon as you started pouring beer out of your casks you were in a race against time. These casks were not modern pressurized kegs, they were just barrels full of beer. If you had a cask of beer sitting around half-empty for a long time it’d go flat and possibly spoil. The problem was made worse by incompetent or unethical pubs watering down the beer, pouring undrunk dregs from people’s cups back in the casks, or just generally fucking up sanitation. In later centuries some breweries would actually send employees around to pubs and check the gravity (the density of a liquid) of their brewery’s beer to make sure that it hadn’t been watered down.

So, while you could theoretically STORE 50 casks of beer sourced from different breweries in your cellar having them all tapped and ready to serve at the same time would have been a nightmare and a very good way to end up with a lot of flat and possibly spoiled beer. So, this sort of thing wasn’t really done.

Of course, you can serve a greater variety of beer if you bottle it, but bottled beer has only become popular relatively recently. Transporting X gallons of beer in bottles is more expensive than transporting X gallons of beer in casks and that sort of economic concern mattered a lot in the past when transportation costs were higher than they are now.

Also, as any homebrewer can tell you, getting consistent carbonation in bottles with naturally carbonated beer is a finnicky process and can result in exploding bottles if you’re not careful. The modern process of adding artificial carbonation to drinks was only invented in 1767 and it took a while to be applied to bottled beer. So, while plenty of bottled ale certainly existed in the 1800’s, in pubs it was a sideline compared to casks for a long time. For example, in the UK the popularity of bottled beer in pubs only really took off after WW II when the drop in the amount of hops used and the strength of ale had taken heavy hits due to the World Wars, the Great Depression, and post-war austerity leading to some very weak ales that spoiled more easily when served out of casks (Watney’s Red Barrel was apparently infamous for this) so some people started buying bottled ale more often at the time as it was seen as less likely to be spoiled.

It’s much easier to stock a wide variety of beers if bottled beers are popular but that’s only come about relatively recently. I don’t think I’ve ever seen a bar with anywhere close to 50 kegs on tap.