In this paper 100TeV are called “totally ridiculous” but now scientists want to build a new hadron collider which would have that capacity: https://news.ycombinator.com/item?id=39271297
It's 10 Tesla magnets that are called ridiculous. The paper also requires 1000 TeV, not 100.
Oh, blame my reading comprehension skills then
Current record for magnets: 45 teslas.
There's more than just raw strength that goes into making magnets for a collider. It's the combination of strength, uniformity, and enclosed volume which makes things difficult.
They need enough for 1000km of accelerator though. LHC has 10,000 superconducting magnets for 26.7km (some can temporarily go up to 7.7 Tesla).
The energy in the paper is 1000 TeV, ten times as much.