You have to take in the whole, surely - look at Wenger, staying long enough for his legacy to take a massive hit despite what he did for Arsenal. We have to look at the whole and make an assessment based on each stage and I don't think it's unfair to say what can be good on the way up can be damaging once there. What Levy initially did is not in dispute by anybody, what he's done since getting Spurs to what now looks like an apex, undoes a lot of what he did whilst climbing to that peak, or do you think how things have turned out with your squad and managerial appointments couldn't have been any better since c.2017? Levy was really highly rated for what he had done, and this line of thought that he is actually damaging to Spurs by now would have been met with only green smilies back then. If he doesn't change his ways, would you not think he's taken Spurs as far as he is able to?
The pandemic has been ruinous, and perhaps expecting there to be a contingency in place is unfair, but even in terms of adaptation and not cutting off the clubs' nose to spite its face, Levy leaves you on the back foot before a ball is kicked so concerned is he with getting the very best price on a sale that he does not cover the purchasing aspect as anything but an afterthought, to the point he's happy to leave you with nothing at the close of a transfer window. The squad you now have is a consequence of his actions, and without promoting from within or being very smart in the transfer window (loans, free transfers, last year of contract buys), you're going to have to spend a lot just to consolidate your position, let alone progress. As things stand, do you think you're more likely to fall back in line with the Everton's, Aston Villa's (big backers) and other top 6-10 teams or be in a position to challenge for top 4? You were lauded for having a very good team a couple of years ago and there was a point where Levy could've really consolidated that, but was too busy being Levy to look at a bigger picture.
The element of risk and daring to take the next leap is not his lane at all, and fair enough, as that can end in tears, but unless he stumbles upon another Pochettino or you have another squad where the stars align, I'd again think the conclusion is he's reached his limit and will be detrimental if the end game is for you to be a permanent fixture in the CL.
What I do think it's going to be harder for you to do, given Levy's antics, is bring in young and upcoming talent who have their pick of clubs in that 6-10 region, unless of course their agents are strong in negotiations and have exit clauses written into contracts.