I only have one suggestion for the dopamine seekers and that's competing.
Even if you don't enter competitions that often, say one every 2 months, it takes up room in your head. There's the getting fit for it, whatever that may look like, there's the training to hone your skills, planning strategies, caring for and maintaining any equipment needed.
Plus the competition itself, travelling to the venue, waiting around after registration, familiarising yourself with the venue, warmup and competition, whatever packing away there is, awaiting results and unloading any equipment once home.
And the talking it through with like minded friends how it's all going, social meetings etc.
Competing in anything, even if you're not obsessed with it or trying to get to the highest levels but just enjoy the challenge of pushing yourself and the taking part, it can still mostly take over a lot of your time and energy. Leaving nothing much for doom scrolling and shopping. If you've never tried it, it could be the lifestyle you're looking for. It stops you feeling rudderless and gives you something to focus on, so things don't have that slightly pointless feel about them, even things you enjoy. You don't need to be well off financially either, there's lots of things can be done at a low level on a shoestring.
My own shopping addiction got completely out of hand when life circumstances forced me to stop competing. It's always been there but there was always something more important I wanted to spend my money on, so it was naturally curbed. I've spent more from excess consumption than I ever did being involved in expensive hobbies and competitions.