Is there really any reason to limit active ailments?

Other than the currently existing ways to extend certain ailments on crits and so on, why do we not simply have all stacks of ailments deal damage simultaneously? Other than server reasons, which should already be a thing if it was a problem, since all ailments ARE already stacked, just with only the strongest one having an effect, what real reasons are there to not just allow all ailments to do damage?

The reason I am posting this is because I have been playing a fire mage, and currently almost all fire spells revolve around applying ignite in one way or another. This was all good in PoE1 where we pretty much just used 1 spell, but in PoE2 where the approach is often to use multiple spells, they are all fighting for room and stepping on each others toes.

Incinerate does pure ignite damage, so does firewall, and solar orb has an ignite element in its centre. If you combine any of these spells you are effectively reducing, or entirely eliminating, the damage of one of them.

In reality, the way I see it, all damaging ailments are simply crits. All they do is give you a percentage of extra damage after the fact, so I simply don't see the need to limit their damage really?

The more I play the more I just feel like ailments should stack and always be active. I really don't see the point other than some arbitrary attempt to make the ailments feel "unique". Really all that is happening right now is that ailments are just worse critical hits because they can't overlap. Hammer of the Gods/Sunder bleeds or Perfect Strike ignite type strategies seem to be the only viable ones. There's no reason to ignite or bleed with any build that doesn't revolve around huge hits.

Ignite and shock really need to be reverted to a bleed and poison style chance to be applied because the current system is completely impossible to work with. Magnitude on hit is fine though.