The "Pure 5E is the only way to save this game" posts in this thread approach self parody. Want to educate your children and ensure your place in heaven? 5E Want to lose weight and restore your hairline? 5E 5E must be implemented in all games for always ever even chess and Fortnite or the human race is doomed!
Seriously. 5E is not the only way D&D has ever been played and I guarantee you, sure as sunshine, there will eventually be a 6th edition and its rules will be, horror of horrors, Different!
On a related note, I do really love when people use "homebrew" as a pejorative. The entirety of roleplaying games descend from Dave Arneson's homebrew game Blackmoor and Gygax selling his homebrew version of Blackmoor as D&D. There may be DMs somewhere out there who only follow the rules of 5th Edition with zero deviations, but that's not the tradition. People have always adjusted the rules for their own games, whether they were PnP with three players or AAA games with 3 million. Larian's got every right to adjust the rules to suit their needs and some of us, as players, have every right to enjoy it. Whether or not other games have used different editions or implementations of the current edition doesn't deny them that right.