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 always suggest to people that you don't always have to wait for buying opportunities. Because you don't know which is actually the buying opportunity, and when exactly it will come. The price that seems high to you today, maybe tomorrow that price will seem to be the buying opportunity. So I tell everyone not to wait for buying opportunities, to build the habit of buying bitcoin regularly, this will help you to buy on to the average price and it will be risk-free.
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So my thinking is to dump my altcoin holdings for BTC and continue DCAing into BTC only; (also feeling a srong desire to become a node operator in order to do my small part to protect and nurture the network as an aside).
It is good that you love Bitcoin the most. But, sometimes altcoin gives much profit, Investing a portion of your money in altcoin is not a bad practice. But before picking altcoin keep caution, choose those altcoins that have a real-life utility like ETH, NEO, ADA. I don't prefer holding altcoin for long term, but there is no problem to hold a little while and fixed the profit when your target is filled.