I wanted SC on a 23 Suburban I picked up a couple months ago (waited 10 months for build); it wasn't available but I took the car anyway.
WIthout SC, lane keep assist on this suburban is absolute weak-sauce. It will bump me back once if I slowly drift towards the line (after my tire is on the line) and then ping pong me into the other lane line and the next bump usually sends me out of the lane. It is garbage compared to the LKA+lane centering in a 2022 Honda Odyssey we had before - which didn't require a subscription. The Odyssey could effectively drive itself on highways without major curves - it could handle small curves fine and kept me centered in the lane. It actually helped steer the vehicle (and read speed limit signs) with onboard technology; no relying on external data connections or paid subscriptions.
TLDR - don't expect any real steering assistance without SuperCruise. GM's free offering for steering assistance (no subscription) is garbage compared to Asian brands; I believe the paid experience outdoes them. Comes down to whether it's available and worth the monthly cost to you.
I'm not paying for another subscription though wish I had it installed in case I wanted to spring for it on a long road trip.
the running joke in our family is that our mid-$20k accord has a better user interface than our $70k Tahoe...everything simply works faster/easier to use...it also has adaptive cruise with LKAS and speed limit sign recognition that doesn't need a subscription. seems like GM is consistently 5yrs or more behind the industry leaders
GM does offer a large SUV with a lot of room so there's that