Tight purse strings five, six years ago allowed a two decade foundation of success to nearly collapse when the man holding it together retired.
We've gone through two managers that did anything but restore us to glory. And third time around you've got a manager that attracts talent, achieved immediate success in his first season and has always made it clear he needs more. If you ignored the last five years you can claim we don't need more or better players. If you're fine with becoming a Liverpool or Leeds then you can turn a blind eye. But if your business is predicated on clubs long term sporting success you're a fool to do so.
As an aside, awful way to think , bringing up Gudetti's missed goal. (Football) History is made of missed and made chances. If you switched it around, even just single goals you'd be rewriting history and Champions and records of all sorts. Utter nonsense.