anything-llm looks pretty interesting and easy to use https://github.com/Mintplex-Labs/anything-llm

You can use a wordpress based lms, such as Tutor LMS, Learnpress, Sensei lms, etc..

Do you mean these?

https://senseilms.com/ https://www.themeum.com/product/tutor-lms/

Are there any disadvantages of building WordPress based LMS sites?

You can use https://nowpayments.io/ which is a noncustodial crypto payment service with support of dozens of coins and tokens. You can easily create invoices, payment buttons or use the api to build your custom solution.

https://web.hypothes.is/ your friend for annotating the web..

I felt mixed emotions while reading the article. Information technology changes so rapidly and time goes by really fast.

My quarantine side project is a Moodle SAAS, which will offer free moodle hosting with the ability to install any moodle plugins. Current offerings do not allow users on free tier to install additional plugins or custom themes. It still very early, but I appreciate your feedback and comments. https://xeted.com/

Great book, Thank you..