The only possible reason I can come up with for why someone would want him back at this point is purely nostalgia. He has moved on and so have we. I have no idea what he would offer us now and how he fits into the team.
We struggle to break down teams who park their bus. Eriksen had come up clutch on many occasions against teams like that. Either by creating great chances or scoring a long ranger out of nowhere.
There's a tendency among fans to devaluate a player's contribution if he leaves on bad terms. I've seen plenty of people saying Eriksen was terrible in his last 18 months at Spurs. That simply isn't true. Eriksen was mostly very good in the 2018/19 season. We probably endured the worst sequence of injuries any club has faced in the last 5-6 seasons (in PL at least) in that season. Eriksen had to fill in as a CM in a 2 man midfield on a lot of occasions, especially after Dembele got injured against Wolves and then never played another match for us. His performance dropped slightly in that period but he again picked it up when we started playing in the new WHL. People have forgotten but Eriksen was actually involved (either scoring or assisting) in almost every single goal in the NWHL during the first few matches, winning us some valuable points. Without those key points, we wouldn't have finished in the top 4 that season.
Even in the 2019/20 season, just think back to the first game of the season against Villa. We were 1-0 down at home and struggling to create anything at all. But as soon as Eriksen got introduced, we were suddenly a completely different team. Started creating chances, good chances. He didn't score or assist in that match but he was vital to us winning.
He was mostly poor in the 2019/20 season though. That's 6 months, not 18. He lost the fans as soon as he made those comments about a "new challenge". That was a really stupid thing to do. He actually did imply if Madrid or Barca (or Juve) didn't come for him, he'd be happy to sign a new deal (or that's what I got from that interview) but the media conveniently failed to highlight that. He was poor, but so was almost the whole team. So singling him out is kind of unfair. But fans were sort of starting to get on his back in matches as soon as he hit a poor pass or hit a poor set-piece. So when Inter came up with an offer he was basically just relieved to get a fresh start somewhere.
Another issue I have is when people claimed "he switched off" and was to blame for Poch's downfall. No, Poch's downfall was totally due to our deteriorated defence, mainly defensive midfield position. Not getting the chance to refresh the squad is what cost Poch's job in the end.
Eriksen's confidence was obviously low. Plus as we witnessed in the early part of 2016/17, his performance gets impacted when there are issues with his contract. That's not to say that he intentionally underperformed. He didn't just flick a switch and say that's it I'm not going to perform anymore. It's not so black and white. A lot of things contrived to put our whole team and Eriksen in that situation.
Anyway back to my original point about why I want Eriksen back. As I said, we struggle against teams who park the bus. We don't have a playmaker. Sure we have Kane but he creates chances differently. Most of Kane's assists have actually come from the deep-lying playmaker position. But creating chances from that position is a lot difficult when there are 8 defenders between him and whoever he is trying to pass to. Eriksen is very good in and around the box. That's why he provided a lot of assists from the attacking third.
We used to regularly score 4-5 against bus parking teams in the peak Poch years with Eriksen dictating the play. Under Mourinho in this season, we seem enjoy playing against teams who attack us but have struggled against teams who let us have the ball. So far we've struggled against Everton, Newcastle (2nd half). Burnley and WBA. I believe we'd have struggled far less if we had Eriksen either playing as a CAM or from the right.
Anyway, it's probably not likely to happen because we already have too many foreign players in our squad. And Inter would want too much money anyway. But if Inter decide to act charitably, similar to how Madrid did with Bale, and Jose finds space in the squad, I'd take Eriksen back in a heartbeat.