But still, if you dump your altcoin right now, your profit will not be too big because almost the altcoins price is down a lot and it is waiting for the next bull run that can happen this year or next year.
Waiting for better times doesn't always end up well and more often than not you will end up with having less if you stick to altcoins, at least in the long run. Back in 2018 I decided to do something similar to what OP is doing; I sold all my alts except ETH and put everything into BTC which proved to be a great decision. Majority of them I sold with the loss, but I would be at even bigger loss now if I decided to wait.
I worry about the long-term future of their viability. At the time of this writing, it seems as if the sky is the limit and these projects are not only growing, but here to stay. However, things aren't always as they seem and I'm starting to wonder if it may be more prudent to dump and invest solely in BTC which I feel provides the most benefit to society and potentially has the most durability.
During bull everything looks great, but once we hit the bear, true nature of altcoins will be shown. If you want to sleep better and worry less, going all BTC is a pretty good idea. I did something similar few years ago, and I haven't regretted so far.