In the past, the 5e rules contained a large number of rules variants, like the variant for creatures giving half cover, or for encumberance, that allowed the DM to tweak the level of abstraction or detail.
However, the only mention of a Variant Rule I could find in the Index of the new edition is a variant on Equipment Sizes (p. 219, PHB), and the ToC of both published books (which contained the majority of such rules in 2014) has not yielded anything either. I do not have a digital version to search on D&DB, so it’s difficult to check for all mentions of „variant“, „optional“ etc, but this seems to be quite a change from the earlier „there are many different ways to play depending on your taste, all valid" stance of 5e.
Are there no other rules variants in the entire core ruleset of 2024 5e? If there are any, where can I find them?
(For what it's worth, given there is no index entry for them, I would find it useful to have a place where they are all referenced, if they still exist).