The most annoying is when YouTube recommend videos I've already seen.
Anyway, the algorithm is changed periodically, and the AI keeps collecting data about you. All online activity that can be detected, is tracked and logged. All, not just the YouTube pages.
Also, the AI is trained on huge piles of data, so the prediction of what to watch next might be OK for the average viewer, but not OK for a particular viewer. Combine this with payed promotions for particular channels, and you got what we have now.
Last, yet most important, recommendations are not necessarily there to enhance your experience, but to harvest more revenue from your activity without annoying you so bad that you'll give up YouTube forever.
In my experience as a YouTube user over many years, there were times with great recommendations, and times with horrible recommendations. The algorithm seems to change its personality at each couple of months, or so. Another thing, the algorithm changes are not propagated to all users at once, so the changes you saw in the last 2 months might not correlate at all with the changes in the last 2 months of another user.
All the above are just my personal observations, I have no YouTube insight info.
As a workaround, I never open the YouTube home page, and instead open the shortcut for subscription only:
https://www.youtube.com/feed/subscriptions