I see people on TikTok make a big deal about, "this is my only account," like having more than one account is a bad thing?
It's not. And if you're trying to grow a following there, unless you can stay in one specific niche, you have to build more than one following, because the algorithm forces you to niche down.
Also, unlike Facebook, TikTok lets you create as many accounts as you want, you just need a new email address.
If you're trying to promote something there, I suggest the same method. Create a variety of accounts. You can always funnel them to the same products, the same websites, or you could use them to funnel to a variety of things. It's up to you.
Also, you always want to diversify because accounts get shut down all the time, for reasons you may never know. Always diversify.
(Especially on TikTok and YouTube.)