I'm a fan of foraging toys. Even simple ones like a see-saw forager, buffet ball, or one of those awesome wooden puzzler are good. You can also make some by drilling holes in pill bottles. For all of his dry foods (pellets, seeds, nuts, etc.), I'd recommend forcing him to forage for them. Fresh veggies and birdie bread can be put in buffet balls and skewers as well.
I recently learned about the BeakBox. A company in New Zealand recently released it, and it's basically an in-cage music box for your bird. You put your bird's favourite music on it, then they can turn it on themselves, and choose which song they want to hear.
Noah is personally obsessed with pill bottle foragers and loves the sound of plastic bags, Rosie loves gathering nesting material and playing in dark places (she has a tunnel she likes to make weird sounds in), Sunshine loves foraging and investigating new toys, and Birdie likes toys made out of artificial materials (acrylic, stainless steel) to swing around and clank.
While a lot of birds will play with toys, shred things, etc., just for the fun of it, a lot of birds only want to interact with objects if it serves a purpose, such as obtaining food. For example, younger budgies love playing with toys and being goofy, but once they turn four or five, they rarely play anymore. They prefer more "mature" activities such as foraging or chewing bark off of perches.
I recommend giving him "activity" perches, such as perches that he can peel the bark off of, or atoms with chains on it that he can fling around, sisal ropes that he can preen, a perch that you can put treats in (there's a wooden puzzler perch that's both a platform perch and a foraging toy), etc. For example, Oliver's Garden sells a platform perch that has plastic beads inside it that birds try to remove from it. You could also try one of those little stainless steel foraging buckets that you can hide toys, treats, shreddables, and other surprises inside of.
Maybe he'd like toys with moving parts that he can manipulate? There's some great toys, like plastic nuts and bolts the bird can twist and stuff, as well as this new line of metal toys (stainless steel or aluminum) by Busy Bird for larger parrots (i.e., bigger that a lovebird) who are interested in manipulating items to figure out how they work. Here:
https://busy-bird.com/shop/