In today's NFL you cannot realistically be consistently competitive (in terms of competing for the SB) for years without an elite QB for a variety of reasons. SF is a unicorn, good luck emulating that model in today's cap climate.
Fields and Williams/Maye/Daniels are all maybes when it comes to being an elite QB in the NFL. Fields' floor is much higher since already know he's an actual NFL player, but in what I've seen of him I don't see a guy you can consistently count on to lead you deep in the playoffs. So yeah, he's played a few years, but he's still a huge maybe when it comes to the question of "is he the guy?" and the bottom line to me is that if you're still a "maybe" after 3 years, in today's climate...I don't really think you're truly a "maybe", you're a "no".