TL:DR: If your webste clientes use Android 7.0 or earlier (released 2016), you may need to take action to ensure you can still access websites secured by Let’s Encrypt certificates. By Thursday, June 6th, 2024.
That leaves other browser's such as Samsung's one which probably has the most usage, no idea if they bundle root CAs or not.
[1]: https://www.google.com/search?q=number+of+android+users
[2]: https://www.theverge.com/2023/6/16/23763340/google-domains-s...