More open hardware and firmware for sure.
Stuff like Fairphone and Framework are nice steps forward, but those ideals could be expanded to a lot of other electronics, like house appliances.
More open hardware and more community-driven repair hubs would go a long way to help reduce consumer electronics waste and actually help people save money.
But alas, those efforts will always be swimming against a very strong current.

FOSS alternative to OneNote. Proper Note-book system with free-form typing and pen support.

More hardware.

I would like to see a unified and federated approach to the community-driven Wikipedia-like index (list) of information like old-good yellow pages that could compete with search engines. There are “awesome”-lists, ArchLinux list of applications, some Wikipedia lists, etc. All of them are pure gold, but are inoperable with each other and obscure. I would like to see something like a dedicated browser or a webpage showing standardized lists of items with only minimal data: name, description, some types, link to the official website, link to Wikipedia (or whatever).

For example, if I type in “Debian”, it shows me that it is a Linux distribution. It is community based, the newest stable version is “11.x”. For more information, see “https://debian.org” or “https://en.wikipedia.org/wiki/Debian”. Then it offers some related lists, like a “list of Debian-based distributions”, etc.

Of course, federation is a necessity if we are talking about the open and diverse web. One server hosts lists of anime & manga, another one hosts a list of cafeterias in a specific region. Plus, in case of failure, these lists could be mirrored by other websites.

I guess, such a project would make the information more accessible, no more filter bubbles. Also, infrastructure costs would be reduced (no need for a crawling and creating snapshots for every single webpage).

EDIT: *standardized

Repairable customizable car platform. Something that could be configured with many features and repowered as technology improves. There’s no reason a well built car couldn’t last 100 years.