On the ETH chain, Flashbots [1] has decimated profits, by turning MEV into a race to the bottom, where miners wind up with most of the profits that bots ("searchers") create. On other chains there is much more profit to be had. People are making large amounts of money, as you can see here [2] (check out BSC on there, most of those profits go to the actual bot owners).

It's gotten incredibly competitive, and there has been quite a bit of consolidation. You used to be able to make a bot that could just make a few thousand dollars per day. Now you're either making 6 figures per day as part of a team, or a few hundred dollars per day on your own. One of the reasons you need a team and financing is that much of it is infrastructure based - being right next to miners/validators in the same server rack, etc. It takes significant resources to have nodes exactly where you need to have them, in various parts of the world.

It's also feast or famine. Sometimes, you'll wake up with hundreds of thousands of dollars from thin air. Here [3] is a loan liquidation using a flash loan from last week that netted the person that submitted it $366K (that was the value at the time) - in a few milliseconds. The only money they had to have to do this tx was the $1.50 transaction fee. The ~$8 million necessary for the liquidation was flash borrowed from a Pancakeswap pair.

[1] https://docs.flashbots.net/

[2] https://eigenphi.io/

[3] https://bscscan.com/tx/0x73d37b728ebd55088d0d7ccd3f82a485ac3...