I agree with the pessimism. Still there are some chances for mom and pops:
1. The "illegal betting" in the USA is well developed. The offshore operators have a great product and players are used to good lines. Will the new and taxed bookies be able to provide a service with decent lines and bonuses? US players seems to me as very conservative = they do not switch brands as much as the other ones.
2. It is known that any massive advertisement promoted not just the brand but also the whole niche.
So if the offshore bookies do not withdraw, there is a chance, that this whole disaster will not be a complete disaster. US is much more reluctant to block websites (I guess it has something to do with free speech). They seize(d) the domains in the past, but that is not possible anymore, since offshore sportsbooks moved out of .com's.
Blocking the money channels will not help (as it is happening even now), because the crypto as funding for betting in the USA is rising. The offshore operators already count the days until CCs will be unusable and they will go full crypto.
So yes, bitcoin is losing with CCs and Paypal, because is far less convenient and will be harder to convince newbies to bet through bitcoins. But how many times and how long? If the US market rises, the grey operators might still participate.
Affiliates occupy the SERPs in the USA (and in the ****** up Europe), we still have a hidden power to promote illegal operators if they pay decent money, because promoting joke like PaddyPower or 888 does not pay even hosting even without costs for paperwork. I doubt offshore guys will say "the 20 years was fun, now we will go to buy a McDonald franchise".
The legalization is a bad news for me, but not the end of the world yet.
If you talk to God, you are praying; If God talks to you, you have schizophrenia.