Yes, I fully agree. Something should be changed in order to highlight the active tab. It is now impossible to see which tab is active and I keep closing the wrong tab.
When in Dark Mode all tabs are dark. If you have multiple tabs up (like the 30 or so I have open) it is difficult to tell which tab I have active. Make the active tab Anything but black.
I have Firefox in Dark mode too but I adjusted the background colors in Windows display to change the "window" colors title bar,taskbar, start menu to a medium gray. So now the top tab bar of Firefox has the active tab Black and the inactive tabs Gray. this helps to see the tabs too by using the Windows settings to adjust it. Hope this helps as a work around.