KingShadowUK In terms of kernel update, it is still not on par with GrapheneOS, which uses the latest GKI LTS branch revision with version of 5.15.167 for Pixel 8 series for now (https://grapheneos.org/releases#2024100800). GrapheneOS is ahead of Samsung and even Pixel with Stock OS in kernel security patching, and this does not take into account the kernel hardening work by GrapheneOS.
Timely security patches against known vulnerabilities is a low bar and should be expected for any OEMs, although most of those fail to do so. When you look at the Samsung Security Update link in the above post, you can see they have a track record of maintaining 4 years of monthly updates for flagships and then they would be demoted to quarterly updates. Based on this track record one can only expect 4-5 years of proper updates and then 2-3 years of incomplete/delayed updates for Samsung devices promising 7 year of updates, unless they have stated elsewhere that they are committed to a more consistent update schedule. A further search on Samsung XCover 7 shows that it only gets up to 5 years of security updates (https://www.samsung.com/uk/smartphones/others/galaxy-xcover7-black-128gb-sm-g556bzkdeeb/).
In addition to a more complete patching, GrapheneOS achieves a higher standard by defending the system from unknown vulnerabilities through a bunch of security enhancements including hardened_malloc, MTE, restriction of dynamic code execution, blocking native code debugging, disabled JIT, etc (more can be found in the feature page https://grapheneos.org/features#exploit-protection).
It should be noted that enabling ADB exposes more attack surfaces of the system. A less secure desktop OS (without verified boot or equivalent, proper application sandboxing, etc) having greater power to control a more secure Android phone as production device via ADB is kind of counter-intuitive for secutity. Granting higher privileages to an app via wireless ADB also does not respect the principle of least privileages.
The rest of your experience on device efficiency and modem are related to quality of life differences and not security.
At the end it is your device so you are free to do whatever you want on it and evaluate what is more important for your usage, but please note that there is a huge gap between the level of security between supported Pixels with GrapheneOS and Samsung XCover 7 no matter how the Samsung device is configured.