Free Chrome Extension that fixes UX in Google.com

My advice, just start publishing first. I think you will find days more plesent if you simply make a name/brand for yourself that shows the people that you create value! This is only for your situation I'm reading now (making extensions to enhance the experience for users of Google...). Go build that blocker, publish it alongside this, and build a few more without trying to worry.
Get a foundation, then worry about your brand. Make your collection follow a similar layout and start showing it off on different forums. Make a contact form and ask everyone who visits your site of uses the extension to leave a comment or at least rate 1-5. While you are waiting on feedback, make sure you are getting feedback and comments (if nobody responds, you know it's not worth monetizing... But you also get a sense of which ones are more used and needed over others... )

So when you get here, in MY OPINION (only...) You now have data telling you extensions that are loved, hated... you monetize by adding features to the extensions you already built and know are used! Or relaunch all the extensions with the added features from user-requests, but launch it as a bundle (make sure you label them as in "beta" now).

I'm chatty today, and I'm sorry it's so long... But I want to stress that rule #1 is make sure you actually like the solutions you're building (don't try to create what "you" think could be of value... even if you got if right every time, you risk not enjoying the process...). So to sum it up... Build a collection of widgets before you try to $$$ --- and make sure you are attaching some way to get feedback when showcasing them in various forums... The $$ is gonna show when you find trends from the users ( "Dude you NEED to add this feature so I can stop using the other guys extension!!") ...

This is just a theory learned the hard way. Do not think I'm telling you that this is the "only" way to do this. I'm expressing multiple thoughts that can be all thrown away, of only use one. I hope this helps 😊

In cases like this, I think it's hard to go the other direction. While you were able to gain a user base you never validated whether this is something people would pay for. This rules out any type of explicit monetization, such as a one time fee, subscription, pay as you go, etc.

With that being said its certainly worth looking into implicit monetization models, such as selling randomized user data, asking for donations, selling ad space, etc. I don't have any experience in implicit monetization but I would imagine its an order of magnitude harder to make any money through.

It may be more worth your time to ask yourself, "what 'job' is being done by my extension?", by being able to answer this you may be able to figure out some features that could justify a paid tier. You at least have a product out there, it's just a matter of figuring out if you can course correct. This, of course, references Clayton Christensen's "Jobs to be Done" theory.

https://hbr.org/podcast/2016/12/the-jobs-to-be-done-theory-of-innovation.