I’ve always relied heavily on Maps review but for me trust was broken few weeks ago. I went in a restaurant with thousands of reviews averaging 4.6. Food was good but not amazing, service was super kind and proactive but nothing special to deserve a 4.6 in Paris. We understood the trick at the end of the meal. Waiters kindly ask to scan a QR to make a review. You end up on a third-party landing page and if you select 4 or 5 stars you were redirected to Maps, otherwise they simply take your random-internet stars and buried them forever in this landing page. Clever.
If those are complains like "waiter was not nice", "they took 30 minutes to bring my food", I'll assume there's nothing to worry about.
My feeling is that bad reviews are more likely to be more trustworthy, because they are less likely to be faked (unless its the competition).