Have you faced serious scalability issues with it? In my shallow research, a lot of devs complain about Meteor's performance, but it might be misuse or a misunderstanding of how the platform works.
There are number of areas where scalability issues can come up. Most of them are usually due to not well optimized database queries. There was time when real-time data subscriptions were too slow for me with Mongo but now you can seamlessly add Redis for that and bottleneck goes away.
Any particular area you are concerned about?
No! It's just a little worrying jumping in Meteor on 2022, but I might make it regardless. Thanks!