There is no way it would be that easy.
I use lastpass and get asked the same thing, what if someone hacks them and steals all your passwords. Well lastpass has been hacked but as with everything my passwords are encrypted so there is no way for anyone to access the passwords even if they are hacked. It will be the same with truelayer.
No one has ever had their passwords stolen via lastpass or their back accounts accessed in a malicious way via truelayer.