After many requests, I've made an incredibly simple 4-file Joomla starter template that does not require Bootstrap or Sass. But here's why it might actually be easier to just learn Bootstrap and Sass if you want to get better at Joomla template development, and web development in general.
Full Template Development Guide: https://kevinsguides.com/guides/webdev/joomla/joomla-templates/dev-joom-tmpl
JoomSkeletal Template (no Bootstrap): https://github.com/kevinsguides/joomskeletal
JoomStarter Template (with Bootstrap): https://github.com/kevinsguides/JoomStarter
Bootstrap's 100s of free ready to use stylized components with documentation:
https://getbootstrap.com/docs/5.3/getting-started/introduction/
