Don't know how long this has been in Opera, to lazy to look it up, but discovered by accident the Opera's Reader Mode. When activated it gives you a cleaner page to read with menu-bars and ads removed.
You can toggle it on and off by going into the menu, click on the red O in the top left-hand corner of Opera and in the menu that drops down click on Page and then Toggle reader mode.
Or, look for the book symbol at the end of the web / URL address bar.
I'm going to show how it works by going to my last article uploadeed to DavesComputerTips, where I had issues with my camera batteries:
https://davescomputertips.com/canon-powershot-change-the-batteries-error
Here is a screenshot that shows the page as it normally appears. Notice the menu at the top and down the side and the ad.
Now, I'm going to enable the Reader Mode. The next screenshot shows the same page, no menus and no ads.
Just one button above the article named Customize appearance. Click on that to guess what? Right, customize the appearance of the page. There is not really many options. You can pick the type of font to use like shown, Sans-serif Font (as shown).
The three circles, one whith a checkmark is the theme colour. The first is white, the second is white with a slight yellow tinge to it. The third is the dark theme. The slider at the bottom makes everything smaller or larger depending which way you slide it.
One other benifit, if you print from the reader mode enabled page, it prints up a clean page as well.