You're right to be worried about this. I've worked in Fintech for a while, so I'll break down my current views from worst to best
Worst - Using bank information, routing checking number. Avoid this at all costs. These numbers lead directly to your money, and amcan only be changed by opening a new account. Avoid giving these out.
Debit cards. There's a thin layer separating you from your money, but debit cards are still pretty much a direct line to your money. I don't think I've used mine in years, it sits collecting dust, only used when I need money from an ATM, which I jiggle the slot for first.
Credit cards. Now there's a difference. You're using their money instead of your money to pay for things, and so they will not just let someone drain your account. Fraud is taken more seriously. You must be responsible with them, but you have many more protections. Plus if it does leak, ask for a new one.
Payment with credit cards goes swipe, chip, then tap from least safe to most protected. Tap is near impossible to intercept where swipe is pretty much cleartext. Always tap if you can.
The finally we get to tokenization, e.g. google/apple/Samsung pay or paypal. Another layer where your details aren't even passed from your device to the register, just a one time token that says "here's where you can get your money". This is currently the most secure way to pay for anything.
So I'm not directly answering your question because I would not trust an online digital credit card thing, but I'm trying to say that if you know what you're doing, you can avoid a lot of risk. If you use tap to pay or better yet google pay, you're as low of risk as you can get.
For online forms, use google pay when you can, or things like shop pay (all tokenization providers, and I trust them more than I do random shop owner), and I have a credit card with really high protections for anything I really don't trust