Your EtreCheck report does not suggest a failing CPU, SSD, or a hardware defect.
The strongest clue is the repeated high CPU usage from WindowServer after upgrading to macOS Tahoe.
Quote from @ Grant Bennet-Alder
" WindowServer is the task that makes sure the right stuff is in every window, manages multiple windows in multiple positions on the screen, possibly overlapping or not, and generally manages all issues related to drawing the stuff on the screen. " End Quote
Your MacBook Pro 16-inch (Intel, 2019) uses both Intel UHD 630 graphics and an AMD Radeon Pro 5300M GPU. Since Tahoe was installed, the system appears to be spending more resources on graphics/compositing tasks, which matches your symptoms: fans ramping up during simple tasks like YouTube playback, high WindowServer activity, and very poor battery life.
Ryujinx is unlikely to be the original cause because your issue started before you installed it. The EtreCheck history also shows WindowServer high CPU usage beginning shortly after the Tahoe update.
Your battery is also a factor. A cycle count of 1291 is above the typical design target for this generation of MacBook Pro batteries. macOS reporting “Normal” health does not mean the battery still has its original capacity. A worn battery combined with increased GPU usage can easily result in much shorter runtime.
if you see battery 'Service Recommended' on your Mac laptop
The first things I would try are resetting the SMC, testing with Automatic Graphics Switching disabled, and checking whether the problem happens with only the built-in display. Apple’s instructions for resetting the SMC on Intel Macs are here: Reset the SMC of your Mac
I would also check Activity Monitor while the problem occurs and look specifically at WindowServer, Safari/WebKit, and GPU usage. Apple’s guide for checking Mac performance is here: Activity Monitor User Guide
If the issue continues, test with a fresh macOS user account. If WindowServer remains high there, the problem is likely system-level and related to Tahoe’s graphics stack. If it disappears, a user-level item such as an extension, driver, or background utility is more likely.
Your report does show some older third-party components (such as Java, Huion software, and old launch agents), which are worth temporarily removing or disabling for testing, but nothing in the report clearly identifies one of them as the cause.
I would avoid reinstalling macOS or blaming individual apps until these tests are done. Based on the timing and the WindowServer behaviour, a Tahoe graphics/power-management issue is the most likely explanation.
