Are 1500s actually good, or just better beginners?

A 1500 should play at the level of a 1500, that's what the rating means.
However, some will be underrated because they're improving or recovering from a bad period.
Many will have an 'unbalanced' profile as they will play certain parts of the game better than others. Some like to attack but are weaker in an endgame. Others play sharp openings with traps they've memorized.
In short, yes, a higher rated player can lose to a 1500 but if it happens repeatedly they won't be higher rated anymore.

Does anyone else find 1300s and below so strong? I get paired with them sometimes in arenas. I feel like they play boring openings like the London and don't blunder. Or maybe they do and don't notiuce because of my bias. That's my feel anyways.

Not good here, maybe 1750 here is start of good

@Anon1mouse said ^

Does anyone else find 1300s and below so strong? I get paired with them sometimes in arenas. I feel like they play boring openings like the London and don't blunder.

I know what you mean. I'm starting to think there are two types of player at the 1300 - 1500 level. The first takes advice from the likes of Gotham and others to learn and play one opening for white and one for black incessantly until you master them (me!) and the other takes the opposite advice that you shouldn't learn openings until you're more advanced and should instead learn opening principles and how to apply them.

If you play one opening all the time, you'll eventually fall for every trap and learn from it (I have the scars). You will stop blundering, but you're still not that good. It's therefore difficult to eke out an advantage against that sort of player even if you feel they're not playing great chess.

That's exactly where I am right now. I've learned enough of my chosen two openings that opponents at my level generally can't get an edge, but ... then what? My challenge is how do I take a successful opening where I haven't blundered or given my opponent anything and turn this into a winning attack. So I'm now pivoting to learning to apply opening principles in an effort to play more flexibly and get away from "good opening, shame about the rest of the game"!

@haroldlewis said ^

If you play one opening all the time, you'll eventually fall for every trap and learn from it (I have the scars). You will stop blundering, but you're still not that good. It's therefore difficult to eke out an advantage against that sort of player even if you feel they're not playing great chess.

Oh thank you, that's what I was thinking of. And in rapid or blitz games by the time I get to the endgame I'm mad cuz I shoulda won already, so I spend even more time thinking till I get into time trouble. Then I start blundering, but because they played some setup with no thinking they still have plenty of time left and spot all those nasty forks.

@Iateadogyesterday said ^

I recently went through many games played by 1500-1600s, and the sheer variance of game quality is wild. As a 2050 elo player it makes me wonder, what does it actually mean to be good at chess? Is 1500 elo really a respectable milestone, or are 1500s just better beginners who understand the game a bit better? What do you think?

I think 1,600 to 1,800 is considered good milestone but 1500 is really good novice

Personally I celebrated (to myself) every time I gained 100 rating points. Like when I finally got to 1500, then 1600, then 1700, etc.
1500 is about average I think so it would be a good milestone,, that you are above average here. That's my opinion anyways. Most of my friends in the real world would probably be <1300.

@Anon1mouse said ^

1500 is about average I think

For rapid, the average on lichess is actually around 1410 (I am Mr Average!) - the stats are here.

A baby and a preschooler are both beginners, but once we learn the basics, calling someone a beginner can become more of an insult than a description. Society is constantly measuring people on different scales, and chess ratings are one such scale.

A chess rating tells us how someone performs, but not necessarily what they are capable of, or how seriously they want to pursue the game.

Some people have the ability to improve but choose not to. They may prefer playing casually, exploring new ideas, or avoiding the stress and obligations that can come with competing at a higher level. I've known people who were capable of becoming managers but preferred to remain among the workers; I imagine chess has similar cases.

For me, much of the pleasure comes from novelty and exploration. Others may care more about competition, recognition, or achievement.

So a player sitting in the middle of the Lichess distribution isn't a beginner or even a mediocre player who hasn't progressed. They may simply have found a comfort level of play that suits them.

Competence and ambition are different things.