I've literally never said we need a backup for Bruno. Why? Because Bruno plays every game under every single manager, is never injured, and is club captain. You don't buy a 60m backup on 200k per week for competition for your captain who plays every game and never even gets subbed off. You use just have a versatile young player there for that role in case of emergency. But as it is, Mount won't play as a 10 pretty much ever. And just to clarify, I don't want us to sell Bruno. He's pretty much always our most important and effective player. We have a lot of team development to do until it makes sense to replace him. I'm just saying the Mount signing was obviously dumb and it remains dumb as he remains without a role in the team.
Depth is great. You need depth. You need to know where you need it though. In the 90's teams, we played 442 and rotated our strikers around, so yes we had 4 strikers. Who was our backup for Jaap Stam? Who was our backup for Beckham? You don't have great depth for every player. You have it for players that need rotating. It makes sense to have depth for wingers in our team. It doesn't make sense to have it for Bruno. It makes sense to have depth for Shaw as he's injured often. It never made sense for Spurs to focus too much on depth for Kane as he played every minute of every game (until the injuries).
Also funny you mention City. Maybe have an actual look at their squad. They have a group of 16 senior outfield players. The rest are youth players. Even from that group of senior players, guys like Nunes barely play and only played earlier cause De Bruyne was out for ages. Just like how they spent 40m on Phillips to make up numbers but he never played.