Idle games are usually not optimized for performance. It's running bigint style operations in a tight loop. Mobile phones are not what you should be playing these games on.

Well, I had no problem in playing Swarm Simulator [1] in my phone other than that incremental games intrinsically need an enough screen to be aware of everything. In the case of the Universal Paperclips, its simulation step is too slow (e.g. its handling of projects is suboptimal) that its internal clock will drift over the time. That's why it reports far less time in the notification than the actual wall clock.

[1] http://swarmsim.github.io/

Was able to play this just fine on iPhone 7 Plus

Ah. JS crashed on my mobile at about 30M clips...