Where it helps
Sign-ups you won't use again, apps you're just trying, and listings that need a public contact are all places your number would linger.
You only need one code, so a one-time number is enough, from $0.09.
What panelhi keeps
SMS for your numbers are only visible in your account and never published.
You sign up with a username and password; email stays optional.
What it can't do
You can't call or send texts from a virtual number. It only receives SMS.
Services that only verify by voice call won't work.