When Baremetrics and Buffer started to share their numbers, it was a genius marketing move. Everyone talked about them, for some increased credibility and gave some confidence they are not some obscure company that didn't care about their users.
However, these days I simply don't see any marketing benefit of this. People got used to it, they saw that being transparent doesn't necessary mean a great product or a one that can't fail, maybe they get even a bit skeptic because they look like an experiment than a real company.
And probably the biggest downside, the copycats. The barrier to copy a product is very low with the amount of tools we have right now. I'm very sure that a considerable amount of users look at revenues and think if they can build something similar. Most don't act on it, but some do. When you're struggling at 1-2k per month, you really don't want to see copycats popping up, it breaks your mental state.
Of course you can't avoid that, but exposing your numbers like that you're inviting other hungry developers to replicate your small success.
Can anyone convince me in 2020 it's a still a good way to be transparent, beyond egocentric reasons?
You need to reveal the entire code. The view that incorporates the picker and the whole code for Team for. Otherwise, we are able to simplest offer limited remarks. https://similarpng.com/chef-muslim-woman-in-hijab-transparent-background-png/
Let's end with it's not for you.
For some people the entire process makes them better.
The first cook to put an open kitchen the guest see into, did it cause he had no money to build the wall... Than he succeeded and others copied. Than everyone comes with theories. It might have been the same success with the wall, no one knows for sure. For some this attracts better employees. For some it make them better themselves and they ware it all out in the open and that increases motivation and other emotions and actions. If that just helps you show yourself and your "an attractive person" it helps you with your customers. If you do it cause someone told you it's a good tactic, but you don't have a real reason why, it won't help you one bit. If you doing it while feeling forced to by external reasons it would just work against you. So, not for you, don't do it.