Solasta didn't not sell huge numbers because of its system and mechanics. It sold small because it was the first project of a small indie studio made on a small budget. If they had Larian level resources and marketting, they absolutely would have sold better because they would have had the money to make an even more robust version of the game they were making and it would have been able to reach more people. BG3 has a set of tie-in magic the gathering cards depicting all the companions. Saying Solasta didn't sell well because of how loyal it is to 5e ignores all the far greater factors that influenced its sales. Maybe their loyalty to 5e played a part, but I think that compared to other facters, it's not that big a part.
If the developers of Solasta had a budget the size of BG3's they would have had to make compromises similar to Larian, when the game has such huge hype, such huge player numbers just in early access they would have been forced to consider that the vast majority of their player base would have been far more mainstream and new players. But whatever the case the game did not do well even for a small sized game. It might not have made even the budget that was spent on it back...less than 10k all time peak players. I'm not sure that it did well enough to keep the studio alive, much less allow them to elevate to bigger projects.
I don't follow stats and sales numbers so I don't know what place Tactical Adventures is in at the moment (they've said they're already moving to their next project so I dunno) but more to the point, I don't think Larian has actually compromised at all. I think this game, with all the 5e changes is exactly what Larian wants. I don't think WotC has had any meaningful impact beyond pointing out changes they were making to the system that Larian actually liked and decided for themselves to put into the game. Larian has never shown any reverence for 5e, even from the very beginning of early access. If anything, I think making the game more 5e would have actually been them compromising.
