However, I'm not sure how far Bitcoin will go, will they continue to update the source code when proof of work becomes completely obsolete? Will Bitcoin instead migrate to a different consensus algorithm, if it's even possible?
PoW only becomes outdated if something better comes along. that hasn't happened. maybe it could, but it'd have to be an incredible concept.
(that's like the dictionary definition of "outdated" btw, "something better comes along")
Yeah. PoW is the most effective algorithm of all. PoS, DPoS, PoB are such new concept but still not as decentralized as PoW. Even PoW consume too much energy, It is still worth it
as it makes BTC more valuable. Same as gold mining which consume oil and power just to mine it.