In any case:

1) They are a small team (some a little over 400 employees).

2) They have over 4 widely different products (web mail, vpn, cloud storage, password manager) - and now they're integrating Notes.

Those a hard facts.

Now, how does that employee count compare?

Fastmail has same number of employees to ONLY run a web mail offering.

Nord has 4 times the number of employees and has one less product category (vpm, cloud storage, and password manager but no web mail).

So, no: that they're spread too thin is a fact.

You said it was a small team for Proton Drive. I also feel they are prioritizing more products instead of investing in improving their current offering