How to unlimit bandwidth? (not limit but unlimit)

I’m a total Newbie and standing in front of the following problem:
Our internet connection is 200 mbit/s up and down and it is easily obtained by a desktop computer connected directly to the modem/router from our ISP. All other devices (around 50) are connected via wifi through Ubiquity routers which are connected behind a Mikrotik.
I activated the graphs option in the Mikrotik and it clearly shows that the total bandwidth by all 50 devices averages at only 15mbit/s and the peak speed in one week was only 52 mbit/s, even though I have been running multiple speed tests which should utilize the maximum bandwidth.

I understand that you limit the bandwidth with queues but we don’t have a single queue active in our system.

Why isn’t the total bandwidth, while doing test downloads the same to the bandwidth available from our ISP?

As I said I’m totally new to this and the person who installed the Mikrotik initially is not available anymore.

Thanks a lot for helping out

Which Mikrotik device are you using?

Please supply a drawing that shows what is connected to what. Also export the config for the Mikrotik router and post it here.
To export and paste your configuration (and I’m assuming you are using WebFig or Winbox), open a terminal window,
and type (without the quotes) “/export hide-sensitive file=any-filename-you-wish”. Then open the files section
and right click on the filename you created and select download in order to download the file to your computer.
It will be a text file with whatever name you saved to with an extension of .rsc. Open that file in your favorite
text editor and redact any sensitive information if desired / needed. Then in your message here, click the code
display icon in the toolbar above the text entry (the code display icon is the 7th one from the left and looks
like a square with a blob in the middle). Then paste the text from the file in between the two code words in brackets.

Without these we would simply be guessing.