>Does a type of alternative make it hard to carry them by foot or by bike?
Just last night we were having family pizza night and realized we didn't have mushrooms. Grabbed a reusable bag -- one that I have used dozens to hundreds of times -- and stuffed it in my pocket and hopped on my bike to the grocery store.
It is an utter non-issue. Indeed, in that case I would never have trusted a classic thin plastic bag but the heavy duty reusable one gives me no concern when it's swinging on my handle as I biked home.
When we first got rid of plastic bags here in Ontario, Canada, early on I'd often find myself at a store with no bags, so I went through the period of accumulation. Not to mention that a lot of stores went through a malicious compliance where the bags they sold were terrible and barely lasted more than one use.
Eventually habits changed and now we as a family pretty much never get new bags, and the options stores sell are significantly better, and are truly reusable.
And like someone else said, plastic bags (and plastic straws for that matter) were an absolute scourge, litter wise. Antisocial litterers, blowing out of garbage, etc. Now I never see them. From an environmental perspective -- meaning I like walking my neighbourhood without seeing trash blowing around -- it is a massive improvement.