It’s a complex topic.
Responsible Disclosure is a thing because, on the whole, Vendors proved time and time again they couldn’t be trusted. Standard response to a vuln report was, in order - Denial, Lawyering Up and threatening the researcher, then Including at best a fix in the next generation of the product, and not crediting the researcher, or in many cases, not fixing it at all.
So yeah (and this is before something like a bug bounty existed) RD established a number of things; a reasonable deadline for response (and a further, reasonable deadline for disclosure if the vendor didn’t fix it), a common repository for embargoed disclosures (CVE and similar) and a common policy on what would be demanded of the vendor (basically, a fix, and a public acknowledgement of the vuln and the role of the researcher in finding it)
Now, I generally approve of bug bounties (the info is valuable to vendors, and if independent researchers weren’t doing it, they would have to pay for that work to be done or only find out after criminals started exploiting it) and note they started out fairly small (a t-shirt and other merch, licences to software and so forth) and have grown over time to the point there are third parties that can make a living just managing those programmes for companies)
Bug bounties DO have three problems though. The first is, as you say, that some classes of researcher will deliberately bounty-hunt and concentrate on what gives the best bounty, which skews the goals a bit.
The second is that many vendors say “you must follow OUR rules or lose the bounty” which can mean a bug goes unpatched for a year or more, because the vendor doesn’t want the negative publicity or wants to wait for a model to end-of-life so they don’t have to patch it.
The third is “fairness” - a lot of researchers will feel resentful when they report a serious bug to a programme only to be told “oh, we decided that is out of scope and won’t pay for it, but thanks for finding it for us!” - and will instead just disclose the next bug they find (and they will go out of their way to find a related bug the vendor didn’t patch) purely due to their grudge.
Money ALWAYS changes the game.