Elastic belts are free size and normally don’t tear at all. meaning they can last for life.
I am kind of surprised that they are not commonly recommended in the anti-consumption/ buy it for life communities. Despite the fact that replacing normal belts with them at scale would save the world shitload of resources that are spent on normal belts annually.
Side note: I don’t recommend wearing jeans or suit trousers on daily basis, as there is more durable options that can last for longer time.
Photo is for example, as this is a generic item.
I just started making my own belts. Most leather belts are made of thin veneer of leather. It might even be marketed as 'top grain leather" to make it seem special. Get whole grain leather.
I bought parts from one of the last Tandy Leather retail locations. Brought them home and used my hole punches I picked up at Harbor Freight for a different project and some grommets I got for a different project and made a belt. Out of pocket cost was maybe $16. That belt will last me decades.
In theory I could knit some belts with any number of sturdy materials like leftover metal cables but I have never felt the need.