Do look at the ratings, but don't look at them in isolation. There are many things that go into producing a performance - orders stats, involvement, chance of success, attribute balance, and good or bad player (performance factor) etc. But ratings are your feedback on that performance.

Player 2 has better ratings and match stats. But there are other things which is why more info would be needed.

Imo there is no issue with the ratings except that the way ratings are calculated favours players who might have less to do but more opportunities to grab the headlines ie Strikers. MCs and DMCs make up the engine room in most matches and are more involved in tackling (fouls/success) and passing (possession loss/complete). Cards depress ratings but are more prevalent for MCs.

6s are imo neither bad nor good - indicates a player did good or bad in equal measure or had little opportunity to do good or bad.

The assumption for this is that ratings range from 3-9 so 6 is taken as the midpoint. If ofc the engine's assessment of average is higher than 6 rating then the statement above is not applicable.