Is merge mining with sha256 algo still a thing?
I know that some pools offered merge mining of BTC with NMC but since I only solo mine, I don't know if it's still offered and current?
Merge mining uses the same hash rate to work on two blockchains at once: the original blockchain (e.g. Bitcoin) and the merge mined blockchain (e.g. RSK or NMC).
Note that it is mining 2 different coins so it is NOT a faster nor more efficient way to mine Bitcoin. It only benefits the secondary coins. Even more to the point, the block rewards originate as the secondary coins and do not count as finding a BTC block. Depending on where you are mining those may be converted to BTC but of course they have a much smaller value then BTC.
For my part I never really understood how merge mining could secure two blockchains at the same time? Knowing that NMC allows merge mining but that BTC does not allow it if I understood correctly, is that what you mean when you say that it benefits only to the secondary coin?
I know that some miners could take advantage of merged mining from a financial point of view, but isn't it a waste of submited hashes from a BTC's blockchain point of view ?
I don't understand technically how they can earn BTC knowing that their submited hashes doesn't count for the BTC block