Two others I mourn the death of, as in, it’s more often done wrongly than not, at least on the Internet:

“Led” as the past tense of “lead”: I basically never see it any more. People just use “lead” for the past tense; and

Singular “die.” People just use “dice” for both plural and singular. Though I occasionally see plural “die.” I hate this.

Learned this over 10 years ago and now it’s the only way I tie my shoes. Life changing.