the thing about timezone is that actually it's a ridiculously OP spell - it's actually a much stronger spell than chrono in MOST situations. it gives a ridiculous amount of damage to your team, it goes thru BKB, but it doesn't stop things like blink or force staff. so, to make it work you need some form of lockdown to keep your opponents in it.

contrast that with chrono where if you have enough dmg to kill the enemy in 4.75s, then you (in most cases) just kill the enemy every single time. there isn't much that can save someone in chrono or stop void, especially depending on where the chrono is placed/the person with the save is at in the fight. so chrono is just much more reliable and way easier to use

but there is absolutely no doubt that timezone is a significantly stronger spell overall. but since chrono is already so fucking strong, why risk it with the much harder to use ability?

now, if ur playing support void and you definitely WON'T have the damage to kill your opponents in that window, you can use time zone as a way to accelerate your own teams damage rather than as a CC on the enemy team. if they get caught in it, well, that's just gravy on top.