For sure, for technically capable-people it's not a good idea as it goes against sovereignty. But for normies... they freak out when they hear they need to secure 24 words somewhere... Multi-signature is another option but again it's just not for beginners really. Beginners need to know someone has their back, even if they need to pay a monthly fee like to Ledger.
Having this as just an additional option I think makes sense, I heard Pascal the CEO of Ledger talking on the WBD podcast and he does make some valid points... the current best practices we have work just fine for a small set of people, the rest get freaked out and keep their money on CEX platforms which is a terrible idea.
Indeed the passphrase can be brute forced, but you can adjust your security depending on the threat level. If you're like a potential target in a hostile country or something like that, you want to go more secure; if you're in a relatively peaceful place where the possibility of seizure is not that high, I think you can get away with a shorter one, just so you fend off any smaller attackers that might get a hold of your seed phrase.
So for myself and close people, I'm sure I'll definitely stay away from such a service, as I can secure my seed just fine by myself. But I can see some cases where I talk about bitcoin to less technical people and seed phrases come up, and the option to use such a service might make sense for their particular situation.