Which is better for gaming?

The QN85A. It has a confirmed 120Hz panel and four HDMI 2.1 ports, which is what you need for 4K120 on a PS5 or Xbox Series X. Product B's 144Hz claim conflicts with a 60Hz figure in the same listing, so don't count on it.

Are they the same panel technology?

Both are Samsung Neo QLED, which means quantum dots over a Mini LED backlight. The QN85A's dimming and brightness are well documented; Product B's are not.

Which has better voice control?

The QN85A, because it supports both Amazon Alexa and Google Assistant. Product B lists Alexa only.

Is Product B worth stepping up to?

Only if you confirm its real refresh rate and panel details first. On paper it offers nothing the QN85A lacks, and its listing is inconsistent.

Which handles a bright room better?

The QN85A has an anti-glare coating and high brightness, which suits sunny rooms. Product B's coating is not stated.

Do both support the same streaming apps?

The QN85A runs Samsung's full smart hub with all major apps. Product B names only Disney+, so check for the apps you use.

Samsung Neo QLED 4K QN85A vs Samsung Neo QLED 4K TV

Both are 65-inch Samsung Neo QLED 4K sets, so the picture technology is the same family. The QN85A is the known, widely reviewed model with a full Mini LED backlight, four HDMI 2.1 ports and 120Hz gaming, and owners rate it highly. Product B's listing is inconsistent on key specs, so treat its 144Hz claim with caution until confirmed. Buy the QN85A if you want a proven set; consider B only if you can verify its panel and refresh rate in person.

Choose the QN85A if you want a proven Mini LED set with four HDMI 2.1 ports, 120Hz gaming and a large base of owner reviews behind it.
Choose the Neo QLED 65-inch if you can confirm its actual refresh rate and panel details before buying, since its listing contradicts itself.

Prices

Samsung Neo QLED 4K TV: $1,099.99 at Best Buy (checked today)