If someone recommends an account to follow and it looks blank to you, it probably isn't actually blank! It probably just looks that way when you view it from your server.
If you follow the account, future posts will start showing up on your server.
It is confusing, but there are really good reasons why it happens. You can read more about it (including how to check what a profile really looks like, and how to prevent your own profile looking blank) here:
https://fedi.tips/why-does-someones-account-page-look-completely-blank-is-it-really-blank/
Blocking & muting accounts with few posts and few followers is a harassment-prevention strategy that is a holdover from Twitter.
It works to thwart coat-tailing, sock puppets, swarming, advertisers, and targeted harassment campaigns.
i have a few follow requests in limbo like that and it's because they're almost assuredly part of the groups mentioned but they gave up on the instance they spun to try and follow me due to no bite
but it's still cached in there, despite the instance they tried from no longer being up