I spent a long time stuck on bench, plenty of it around your numbers of 150lbs - my issue was lack of volume.
Just now I'm benching 3x a week -
135lbs for 3 sets of 12 following press work
190lbs for 5 x 5
Topset for 5-1 reps then 4 backoffs @ 90-95%
Recently hit 225 for the first time which was a "goal" I never thought possible when doing the standard 3x5 LP. Some more to come as well. Unfortunately my press sucks and is taking a back seat for now.
Volume volume volume!
Not the biggest fan of microloading the bench. I mean it works and you should buy the plates (especially for the press), but I'm not sure that level of precision beats out just doing a lot of work at 70-90% 1RM. If a guy isn't watching his diet or sleep then he could be up with a crying baby all night and simultaneously drop four pounds bodyweight just by not eating as much Chinese food, and end up shaving 5-10 lbs off what he can do for fives that week. I feel like the variance in actual ability at the 90-95% 1RM weight range for upper body lifts can be wider than the variance in weight of the microplates. However, the more you can tighten up that sleep and diet the better. But I feel like it'd be better to just get a lot more work in vs just depending on microplates when your sleep and diet isn't well controlled.
There's your problem I'd say. I'm not saying you're born to suck at the bench, you're probably just too skinny up there right now. You can widen those shoulders and thicken up those arms.
A lot of high profile guys in the Starting Strength world have been benching since they were teenagers. So then other guys in their twenties and thirties with tiny upper girdles initiate the program and hit the wall repeatedly and start thinking they just suck at this hobby when in reality they're comparing themselves to guys who have hundreds of hours and poundage of bench under their belt.
I feel like my course wasn't entirely atypical and I think Gilchrest points this out: lower body stuff proceeds along, but the bench stalls at 165, 175, 185, 190, 195 etc etc. Eventually I'd break through probably just because my muscles got bigger, which takes time. But when you're benching 2x/week one week and only 1x/week the next and then you add the poor compliance of a thirty year old on top of that, you're just not benching a lot compared to other gymbros.
And then you read SS and get the impression you should avoid the other upper body stuff even though it really explicitly tells you that you should, but also makes fun of them enough that you erroneously think you shouldn't.