I do think at some point when the players have fully adapted to the roles, the squad has depth which it does now to a degree we will need to take the plunge. Our defense is magnificent, our midfield when it is finally available should be fine to compete with anyone but with Kane gone and Son getting on a bit the extra bit of quality will be needed.
As fans we have to get over Ndombele, we spent badly on big signings in the past but that is us, other clubs like Liverpool have shown the big money signing is the one to break the glass ceiling be it Van Dijk or Alisson. Heck even overpriced Darwin Nunez has been leading the Liverpool title charge. There will come a moment and it will probably be this summer when the club has to make a call, at least this time it can make a call with Lange & Paratici and not Steve Hitchen. For depth we probably only need 1 more midfielder, a Gallagher or a Emerson.
We have done the right thing up to now, getting youth and building depth with the likes of Udogie, Sarr, Porro, Solomon etc. The next step once the squad is filled out is the elite game changer/s, that is probably the hardest step.