It's probably apt to ask yourself what sort of revenue model you prefer to support for the value provided. YouTube is a rare case where they offer multiple options.
Personally advertising is a high cost to myself that I am not willing to pay. I even avoid restaurants that have televisions, or that play a radio station instead of buying music that has no advertising in it. (I also frequent a couple of places that are willing to leave the music off for me, at least early in the day before the lunch rush, and one that doesn’t play music at all. That’s a different story though.)
I disagree with that. A selection of channels that I watch regularly enough:
The Spiffing Brit doesn’t do sponsorships, and his videos are quite popular (https://www.youtube.com/channel/UCRHXUZ0BxbkU2MYZgsuFgkQ/vid...).
This Old Tony (https://www.youtube.com/watch?v=W9rlWu9KWe8) is not quite as popular, if you count popularity by video views, but still very popular and no sponsorships.
What about Ben Eater? (https://www.youtube.com/watch?v=g_koa00MBLg) He is exactly the kind of enthusiast who would make amazing videos even if all advertising disappeared.
Ross Whatshisname of Accursed Farms (https://www.youtube.com/channel/UCJ6KZTTnkE-s2XFJJmoTAkw/vid...) does an extremely in–depth review of a video game about once a month, and doesn’t do sponsorships. He gets 200k–500k views on every review, which is very popular by any measure.
Posy (https://www.youtube.com/channel/UCmEmX_jw_pRp5UbAdzkZq-g/vid...) is another enthusiast who makes videos for the sheer delight of it and whose videos are quite popular. If you haven’t watched his videos about LCD displays then you haven’t lived.
I agree that truly unpopular videos with a dozen views will never make money, by advertising or otherwise. But the converse is not true; as I have demonstrated, there are plenty of popular videos that don’t bother to try to make money by sponsorships. You know every single one of those is turning down a VPN company every week of the year though.
Either I watch or I don't watch, but I won't watch ads.
It's fine if you want to deprive them of their livelihood which affords them the ability to make professional and polished videos but don't kid yourself about your motivations. And speaking as an amateur videographer, it takes an enormous amount of time and work to be able to make even a short 20 to 30 minute video.