* this is a UK university, tuition is limited to about 30k GBP for a (UK standard) 3 year degree. That's 30k total, not per year. Accommodation is extra.
* Leicester isn't a particularly good university. It's ranked 77th out of 121. 50th out of 68 for maths [0].
* The department has been put on notice a few times that it needs more to up its income (get more students, get more research grants, get more other funding) or cut it's expenses. It hasn't done so.
* There are a whole bunch of wider issues for university funding at the moment. A rent strike is costing them money. Inability to take on foreign students (who they can charge more) is costing them money. A drop in overall intake as more students realise it likely isn't worth the money to get a degree etc. Fewer students on campus means less sales from university bars, restaurants etc. Mix that with high fixed costs and someone has to be let go.
* They're closing the pure maths departments but seem to be keeping the others (Including actuarial science) which is likely what students actually want. Ultimately UK degrees are mostly about getting a job these days, not the beauty of numbers. That's sad but that's the predictable consequence of 20 years of government policy in the area.
[0] https://www.theguardian.com/education/ng-interactive/2020/se...