The Suez canal was built by the British empire with funds from that empire, but couldn't the Ottomans were in control of Egypt for 300 years before the British, and as seen in [China](https://en.wikipedia.org/wiki/Grand_Canal_(China), canals were possible in feudal times. so why didn't, or couldn't, the Ottomans build the canal?
The Suez canal was built by the British empire with funds from that empire
That would come as a shock to the Egyptians and to Ismail Pasha who built the canal as part of an Egyptian/French/British consortium using Egyptian corvee labor.
That being said there was an ancient canal, the Canal of the Pharaohs that linked the Nile (and therefore the Med) with the Red Sea.
As for why the Ottomans didn't build such a canal earlier, I'm not familiar with any need to do so. The point of the canal is basically to expedite shipping between Europe and India or points east. It makes profit by basically charging a toll to ships that do so. When the Ottomans first captured Egypt in 1517/18 there was no European empire in India in need of trade and wouldn't be for several centuries. The Ottoman trade out of Basra was perfectly profitable as it was. While Napoleon was thinking of control of a Suez Canal when he invaded Egypt in 1798, again, I'm just not familiar with any pressing desire by anyone, whether Ottoman or Western European, to do so prior to that. See /u/KimCongSwu 's much better reply below.