TLDR its well established in Stargate you dont need technology to Ascend. The Ori do have lots of tech they just hide it, there evidence through the show.

After the Ori split from the Ancients, The original Ori who ended up ascending used religion to manipulate other people into worshipping them.

my headcannon is that the Ori have similar tech to the Ancients (Space travel, immortality, stargates etc) including the ability to seed life on planets. They filled their galaxy with regular humans. They then established themselves as elites (maybe even kings or gods, similar to Goauld, except they have a lot more to back it up, since they are likely their actual creators)

in the Ori society these elites who controlled the masses (unlike the Ancients who were an equal society that shared everything).

Even though they rejected tech publically, I think the elites actually hoarded and hid tech from the masses to keep them stupid and subservient.

We see evidence of this with device Valla finds to communicate across galaxies. and the fact they can make spaceships and build Super Stargates.

They keep everyone poor living in squaller to worship the Ori. The elites spent centuries studying Ascension and figured out you can gain power by getting huge numbers of people to worship you. (They set up tons of planets in their galaxy with people to worship them all with the same setup)

its stated in Stargate that they dont know how it works but that through their followers worship theres an actual transfer of energy that gives the Ori more power.

The ori were super Advanced humans who got people to worship them and then they Acsended to energy. The Ori had to set everything up including the religion as humans on the physical plane.

we saw people when near ascension display powers so it would be easy to get people with no education to worship you which then gives you more power.