They could take free online classes about a topic they're passionate, watch a movie or tv show on their phone, join an online community to talk about topics they enjoy. There's even the possibility to make friends in online communities (I made some friends like this).

Those are some free examples of proactive instead of reactive cellphone usage that I can think of. My concern lies on the reactive usage (watching tiktok videos all day and then going to sleep).

You don't need a pile of money to go outside. You don't need a pile of money to learn to fix your own things (in fact it saves you money). Etc, etc.

So many people have this idea in their head that it is only worth ceasing the doomscrolling if you are actively giving someone else money.