I have very little information, especially since I don’t really pay attention to transfer rumours, so I can only speculate.
If he’s on £100k or £120k a week, which I think was widely quoted as the normal going rate for a versatile, young-ish Arsenal midfielder who was courted by Chelsea at the same time, while being an England regular, then that works out to around £5m to £6m a year, not to mention any transfer fee. I think this would be a significant obstacle for a lesser team who would be expecting to bring someone like that in as a regular starter, let alone any transfer fee.
On the other hand, for us, it would free up the wages which could then go into someone else, but we’d be losing valuable experience, especially of someone who’s sufficiently familiar enough with our team. Considering that he’s been pretty much our utility player this (and last) season, I’d say that the role he plays at the moment is essentially as a stop-gap filler for various positions should there be drastic injuries, almost like a younger Milner. So far this season alone, we’ve seen him pick up 9 games in total, with 450 minutes, despite having been injured a fair bit himself. In fact, looking at transfermarkt, he’s been available for 10 league games thus far, averaging 31 minutes for each game, although he only played in 7 for an average of 44 minutes per game he’s played in. Of that, he’s started 4 games,
I don’t think he picked up a single injury last season, but he picked up 1526 minutes, which is a decent amount for a squad option. He played regularly between October and February, before disappearing thereafter. He also played all our Champions League group stage games.
I think he has more value to us than to other teams, even though he’s not indispensable, and that’s why he’s still here.
I’d argue that that’s a feature of any top team. There are always many players who superficially offer nothing, but they’re there simply because it’s too expensive to buy someone in to do their jobs, or they’ve fallen into that category like Oxlade-Chamberlain has, simply because of injuries. Maybe they should have been moved on earlier, to keep costs down, but there’s always a cost of turnover, and I’m betting we value that higher than the costs of paying their salaries.
I really don’t think the “sense of staleness” is present except in the minds of fans.