@EricK64 Using a browser with an integrated email client is probably a new experience to you, so you should expect a learning curve for that.
You made a number of points, which I tried to address before. Here are some more:โ
Where is the web browser? Presumably, you were looking at the mail tab. The web browser just uses other tabs and/or windows.
How can I isolate one mail account? In the mail panel, you can work from unread or received folders to view all messages in all accounts, or you can expand All Accounts, and work from the Inbox of any account. Some users may prefer to work from the Contacts Panel.
Where is the Back Button? No, it is not in the Panel. It is on the Address Bar, where one would expect it to be. One can Display All Navigation Controls in the Panel to browse the history of pages visited in the Panel, but that is disabled by default.
The smaller buttons in the Status Bar are: Show/hide the Panel Toolbar, Take a Break, Synchronise, Mail, and Calendar.
The little icons on the top right are standard Windows control buttons to minimise, restore, or close the browser window. Mac or Linux may be different. There is also a Trash icon to list the last 99 closed tabs/windows.
The toolbars are customisable to suit your workflow, but the top right buttons are OS controls, not Vivaldi buttons.
Large, high resolution monitors may be made more usable by increasing the User Interface Zoom in Settings, Appearance.
Please spend some time to make this tool intuitive. The developers spent more than seven years already doing that. Please give it at least seven days before forming opinions about how it should be designed. Then search for feature requests to upvote, or create your own.