Do you ever go beyond level 30?

I recently started my 1000th playthrough of Skyrim (vanilla plus mod list as always), with intention of reaching level 30, because I never did.

I created the most compelling character, a very bad ass spellsword with a great background, motives and etc... And as soon as I reached level 20, and got rich, I lost all the interest because it becomes monotonous.

How do you keep your playthrough interesting tho?

P. S. I only finished the main quest once, and I wasn't that high of level. I'm never reached quests like ebony warrior and whispering door.