I never understood why NOT ascending was an option

After finishing A2 and reaching A3's town I realized I did not ascend. This happens in POE 1 if you aren't aware or particularly focused on getting the trials on each zone.

Why is that? Why is it a core philosophy to allow players to miss out on so much damage / utility?

I can't figure it out... and it looks like it's going to be a thing in POE2 as well.

Blood mage gets worse when you ascend, so it’s nice to have the option to skip it for now.

I mean for at least 1 reason, I got my chaos plague build witch through the trial, saw that the 2 ascendency options we currently have do not go with that build, and at the very statue chose not to ascend so I can wait for the third choice to be added, hoping its chaos oriented.

But besides that they want ascendency to be added power for added challenge. Optional added challenge. Considering the trials ascendency is behind, people would find it annoying if they had to complete the trials as a specific point to be allowed to continue the campaign.
Rather is it's set up on the optional side dungeon way where if your want the power game sooner, you have to complete the challenge sooner, which is harder, or you can wait till later making it easier but not having the power gain as soon.

Honestly, I abhor this specific activity. I did one run in PoE to clear the quest from my log and then never touched it again. Now it's (one of) the ascension mechanic? Nope. Nope. Nope. Guess I'm missing out on some points.

Blaming GGG for you not reading and exploring areas? Lol, lmao even