Reviews are a trust signal for the consumer, not a ranking lever for Google. That's the disconnect most people hit.
LSA rank is driven by a combination of things happening simultaneously: your bid per lead, your responsiveness rate (how fast and consistently you answer), your budget availability the search. Reviews feed into it but they're not the dial Google turns when deciding who goes first.
The two I'd look at immediately are responsiveness
and budget pacing. If your budget runs out Tuesday afternoon, you're invisible for the rest of the week while competitors stay live. And Google is very quietly punishing slow response rates. If someone with 80 reviews is answering calls in under a minute and you're at 4 hours, they're going above you.
Also worth checking is review recency. A lot of reviews from 2 or 3 years ago doesn't carry the same weight as a competitor who's been steadily pulling in new ones. Google wants to see that you're still actively working and customers are still happy now.
Raise your bid, check your weekly budget cap, tighten your responsiveness, and make sure you're getting fresh reviews consistently. The count matters less than you'd think.