I have been running www.theislandwiki.org for ten years. Everything works much as I want it to, despite still using Version 1.17.2; PHP 5.6.40 (apache2handler) MySQL 5.6.44-log. I may move to a new host next year and it would probably be advisable to upgrade to the latest software versions before doing so. However, I am concerned about the continuing compatibility of extensions, chiefly multi-upload, which is crucial to my work because I add up to 5,000 images a year. I have discovered that multi-upload is no longer supported and the latest version released in 2019 appears to be more complicated than the one I have been running for years. I have installed it with 1.34.2 on another wiki and it doesn't work. I am wondering whether SimpleBatchUpload is the answer to my needs if I upgrade Mediawiki. I need a routine which allows me to quickly select up to 20 (or more?) images from my folders and import them into my wiki
Topic on Project:Support desk
SimpleBatchUpload would take care of your needs. And it isn't too hard to install.
There's also Extension:MsUpload