I think it depends on your goals. I have a somewhat lengthy list of companies whose products/services I will not buy for various reasons. I don't consider it a "boycott", though, because my intent isn't to encourage those companies to change. I simply don't want to support them. Doing that works very well for me, because my entire goal is to avoid involving myself with them.

I combine this with another "vote with my dollar" practice -- with everything I buy, I buy as local as possible. Ideally, this is a small businessperson in my community. I do this because I strongly believe that I could not have achieved the success that I have achieved without the active support and investment of my local community -- so staying local when possible is one way I can repay my neighbors for that. That works, too.

If your goal is to change the behavior of large corporations, then yes -- not buying their stuff isn't going to accomplish that unless you can convince a really large number of people to join you. That's a real boycott, and history shows us that its effectiveness is spotty.

TLDR, but the example of not buying beauty products in order to reduce animal suffering is the opposite of voting with your dollar, you are withholding money. Buy beauty products which use humane methods. That is voting with your dollars.