Is maining Poppy Support Viable in M+?

This season, I have been spamming Poppy support almost every game with great success (Currently E4 in Solo Q with 71% wr on Poppy with over 58 games. E1 in Flex).

I have heard around that Poppy Support is only viable as a counterpick in higher ranks (M+) because wall stuns become harder to land and early laning phase becomes much more difficult. In many flex games played with dia-GM, I have not really felt this to be the case. I have always felt useful and like I'm contributing a lot to my team.

Are there any high ranked supports here that can give some insight on whether I need to expand my pool more or if there is some validity to this? I'm definitely going to keep playing her for now since it is working, but also don't want to reach a plateau because of my champ pool.

Thanks!