You seem unable to see a difference between WotC and 5e or Dungeons & Dragons in general. Rest assured some of us here do.
No, I can distinguish between them, but WOTC far and away has the most 5E content, and the most customers. WOTC 5E material also dominates the market of fan content and 3rd party creators leverage that.
If you are not buying WOTC 5E content then you are also not watching optimization videos on that content, buying stuff from DMs Guild that leverages that content or playing in paid games that include that content and that will hurt those 3rd party creators.
For example, watching a video on optimizing an artificer is pretty useless if you refuse to buy the product that includes the Artificer class and are therefore not watching that video, when you otherwise would - that hurts 3rd party creators.
Sorry but if you restrict yourself only to the SRD and 3rd party 5E material you are hurting many 3rd party creators