It seems as though you are shifting all the blame onto 'we', whomever that is. Alli needs to take responsibility as well; don't you think. Three years of generally poor performances aren't good enough.
'We' have been through this, he was hugely overplayed, most especially when we were playing a derivation of Bielsa's high press that is physically demanding and is notorious for burning players out, it's exacerbated by carrying soft tissue injuries that aren't given time to heal - it causes long term serious fatigue issues which affect form and physical and mental control - this is all a matter of documented fact.
'We' was Poch and his lack of rotation - this real-world issue almost destroyed Eriksen and he too is yet to find his way back to anything like his best form, and frankly may now never do so at a time when he should be at his peak.
For three years Dele carried injuries that his advisors should have stepped up and addressed with Poch/the club - agents, when they see a decline/a client going off the boil, do this all the time, I know his agent tried, but in the end and after presenting extensive evidence of what it was doing to his client, it was ignored.
I have no idea if you've ever competed at a high-intensity level week in week out for an extended period, just, believe me, talk to your local sports physio/doctor and even they will be able to explain what underlying issues deep fatigue and soft tissue injuries it will aggravate/it causes and how long that can take to recover from. Once you've spoken to them and you re-watch how disjointed his last two seasons were, you'll spot the mechanical issues and know what to look for and what you'll see, his physical decline and fluidity of movement was what kept telling me he shouldn't have been playing at all.
Our only hope is a long rest, a slow return and we may yet see the best of him again, but Jose has for once got to be patient with a talented player, something which he has already had to have fight with Levy about, and now has another on his hands, it's his career mark for honing in on a single-player and blaming them for his defensive system not working, and despite him saying when he joined that he had 'changed' it's clear that that too was another whopper from him. Every club he's been at he's used a scapegoat, including the now best player in the PL.
I still expect Dele to leave, and if he picks the right league, just watch him regain form and start doing what we are utterly desperate for: an attacking midfielder that can score goals for fun.
So it's time to end this endless debate, and revisit it in a year's time and see who was right, but even if he stays, in Jose's system, any midfielder is not going to score regularly.
Eventually, we'll get sick of his brand of football, just as the chav and the manure fans did - but a couple of pieces of silverware that he might deliver will still be what fans will think was worth it, but alot of us won't - I'm almost thankful that I'm not spending a penny watching them whilst Jose does what he does.