You bypass limitations to get the fastest possible download speed allowed by your internet connection.
A Debrid service acts as a . You pay one subscription (usually $3 to $10 per month) to a Debrid provider. You then paste the URL of any file (from Tezfiles, Rapidgator, Uploaded, Mega, etc.) into the Debrid website.
Buying a premium account directly from Tezfiles fixes the speed, but it locks you into one specific file host. If you find a file hosted on Rapidgator or Katfile next week, your Tezfiles subscription is useless.
A Tezfiles subscription is usually more expensive than a generic Real-Debrid subscription because it is single-source. Real-Debrid is cheaper because it aggregates many different file hosts.
Since the debrid service handles the interaction with the file host, you never have to look at a "Please wait 30 seconds" timer or solve a puzzle to prove you aren't a robot. You paste the link, you get the high-speed link, and you download. It’s that simple.