I doubt it. I don't think Slot was that bad, but he inherited a very good team and then Salah had the best year of his life. But, I don't think Slot was what was holding them back.

Salah, Van Dijk and Robertson were the last 3 key people remaining from the absolutely amazing team that Klopp built. Salah's form declined, and now he's gone. The other 2 are still there, but at 34 and 32 respectively they're almost certainly not going to have record-breaking seasons again.

They've bought well over the last few years, but they were never going to be able to replace prime Salah, prime Mane, prime Trent, etc. I think they're buying from the pool of players that Arsenal was buying from in the mid-to-late Wenger years. They're the kinds of players who have to take a small step down from one of the world's top clubs to one that's not quite at a title challenger stage (Ozil, Alexis) or who are unproven in the Premier League / Champions League but may come good (Cazorla, Giroud, Aubameyang) etc. Other contenders like Man City and Arsenal can sign players who are at the absolute top of their game and want to play for a club that is very, very likely to be challenging for the title. It may just be half a step up, but it can make a huge difference.

I think they'll be a definite top 4 challenger, but it will take a near miracle for them to win the title again soon (and I count Salah's form last season as one of those near miracles).

I don't think Iraola will have a good time there with the lack of the control a head coach has in that organization

Honestly I didn't think he did that bad.