If we categorize on-chain arbitrage difficulty levels, I think this ranking is more reasonable:

Ethereum's difficulty is roughly medium. As long as you understand some contract security knowledge and know a few reliable developers, you can basically find opportunities to make money. The ecosystem on this chain is mature enough, and arbitrage opportunities still exist.

BASE chain is much more complicated; I would give it a 7 out of 10. There are indeed many application projects, but scams are also emerging endlessly, with all kinds of small coins popping up everywhere. Founders posting contract addresses daily to harvest users has become the norm. To make money here, you basically need to be someone with real skills and knowledge, and you have to think carefully to avoid pitfalls.

BSC is the simplest. When the market is good, almost zero threshold; projects recommended by the official can double in value just by buying, and selling to cut losses always results in profit. This chain has the lowest difficulty level, suitable for beginners to gain experience.

SOL is truly hell mode. Last year, it was still playable, but this year, the entire ecosystem's difficulty has skyrocketed. Only top-tier projects can make money; small coins often hit the daily limit and then go to zero. If you play SOL without illusions, you can still make some profit, but the psychological pressure is enormous. The whole process is spent in high tension, feeling like your brain might collapse at any moment.