Manchester United's glory days are well behind them now and i know their fans definitely want more, but i wouldn't say they are in a "crisis" just yet. The fans want the Glazers out, but they aren't going anywhere for now, though they are about to sell 25% of the club to Jim Ratcliffe, i don't know if that would help the club move forward a little bit, but we'd have to wait and see.
Manchester United have been struggling to achieve success like they used to have since the retirement of Sir Alex Ferguson. Many coaches came and left the club but failed to bring success back to Old Trafford. Glazers can be out or stay but if their club won't change strategies from player transfers, player salary to more things and won't have long term plan, they will continue to have many bad seasons.
They have to look at clubs like Arsenal, Liverpool and Manchester City that all gained success after sticking with their long term plan. Manchester United can do the same but they must start to change from their club board members who decide many big and decisive strategies for the club.
It is hard for United fans to see their club so far from the top level of European football, but it is what it is, they have to keep on trying until they get it right, that's why so many managers have come and gone, and Erik Ten Hag might be the next manager to get fired, his team are on the verge of CL group stage elimination, and they do not have any chance of winning the EPL this season, the pressure is definitely mounting and prolly sooner or later he would be sacked.
They are almost out of Champions League and if they will have to continue this season in Europa League, it's hard for them to play well in the second tier league in Europe. The last season is a bad one for them in Europa League and so far in this season, Manchester United did not show that they have big improvement in their squad quality as well as performances.