Suggestions for creative web projects for a web developer to create

I've a not very bad experience with web, I'd call myself intermediate, and I've some free time to spend so I was looking part-time projects to work on. What ideas do you suggest? I'm looking for something medium complexity, that's free to create (I don't have a billion dollar credit in Google Cloud), wouldn't require a great amount of effort or a group of people to create? I like to create open-source, simple UI yet modern, mostly free (profit would be nice, but the main point).

Questions that may help:

1- What's a problem that you meet in your every day life that a proper web project could solve?

2- What's a site that you use often, but usually flooded with ads, and you wish there was a free alternative to use?

3- What app would you pay for if you found a good alternative (donation or monthly subscriptions)?

4- What's a feature that's extremely useful that you wish it existed in one of the apps you use frequently?

5- What project you wish it was more privacy-oriented (therefore free open-source project)?

While this post is mostly focused on web projects, it's OK to include other types like Windows, macOS, mobile as someone else may see it, and probably work on it.