Which is better for gaming?

The TCL T7. It has a 144Hz native panel and a 288Hz variable gaming refresh mode, while the Samsung tops out at 120Hz. The Samsung still handles consoles well, but the TCL gives high-frame-rate PC setups more headroom.

Does the Samsung QN85A support Dolby Vision?

No. It supports HDR10, HDR10+ and HLG. The TCL T7 adds Dolby Vision and Open HDR, which matters if you stream a lot of Dolby Vision movies and shows.

Which has the better picture in a bright room?

The Samsung. Its Neo QLED mini-LED backlight and anti-glare coating produce higher brightness and deeper contrast under daylight. The TCL is a solid QLED but washes out more when light hits the screen.

Neither has a documented lifespan edge. The Samsung is a 2021 model with a long record of owner ratings, so its reliability is better known. The TCL is newer, so long-term data is thinner.

Is the Samsung worth stepping up to over the TCL?

Yes if brightness, black levels and sound matter most to you. No if you game at high frame rates or want Dolby Vision, where the TCL is the stronger set.

Which is better for a soundbar-free setup?

The Samsung. Its 2.2.2-channel object-tracking audio is fuller than the TCL's 2-channel system. Both decode Dolby Atmos, but the Samsung's extra channels give it more presence.

TCL T7 65-Inch QLED Google TV vs Samsung Neo QLED 4K QN85A

The TCL T7 is the better pick for gamers and Dolby Vision fans: 144Hz native with a 288Hz gaming refresh mode, MEMC motion, and every major HDR format including Dolby Vision. The Samsung QN85A is a 2021 Neo QLED with mini-LED backlighting, stronger peak brightness and better anti-glare than the TCL, and it carries a huge owner rating base. Build and picture polish favor Samsung; gaming specs and format support favor TCL.

Choose the TCL T7 if you play console or PC games at high frame rates or watch a lot of Dolby Vision content.
Choose the Samsung QN85A if you want a brighter, mini-LED picture for a bright room and a set with a long track record of owner ratings.

Prices

TCL T7 65-Inch QLED Google TV: $529.99 at Amazon (checked today)