My short answer is, no, Matter compatibility is not inherently important when making purchase decisions right now. It's a nice-to-have but not a must-have. We've had various types of home automation forever and installed pieces that used different standards, found the shortcomings, ripped them out and replaced them, and discovered new shortcomings.
There is always the next big thing that is going to fix all the problems and work flawlessly. That said, Matter has great promise as a future underlying standard that will have greater interoperability.
Most importantly, how do you want to tie your home automation together? For example, my parents just moved into a new house and I've been able to design their home automation from the ground up. They are iPhone users, so I moved them to an AppleTV which also serves as a home hub and have been setting everything up using Apple Homekit. They are in their 70s and find it really easy to use the Home app on their phones and iPads to control their lights and more. Which brings me to your lock...
This is a fabulous lock! If you're already in the Apple ecosystem, the lock is tightly integrated into the Homekit/iPhone ecosystem and Homekit can act as the glue between future Matter devices and your lock. We have two of the older Encodes and I just installed the Encode Plus at my parents and I'm super-jealous. Setup was a little confusing at times, but it has been rock solid.
Don't go Kwikset. They initially installed a Kwikset and it was just terrible. Garbage build quality, horrible app, kept dropping off the network, batteries lasted only three weeks (!!!), and when you went to replace the batteries a loud lock removal alarm would sound until you removed them. I pulled it out and they donated it after six weeks.
For lighting, we installed smart switches instead of smart lightbulbs. While each switch was more expensive than a bulb, there are far fewer so it was cheaper overall. We went with the solution that was widely regarded as the most stable, Lutron Caseta, which integrates into Homekit using a bridge. The nice part of Caseta is that if you ever want an additional switch, you can purchase a flat wireless switch that you attach to the wall, throw on a switchplate, and it looks like a normal switch. No rewiring required! Another cool feature is that you can link switches together. For example, I set it up so that when they turn the lights on at the top of the basement stairs, all the lights in the basement come on right after, even though there are three separate hardwired switches. I also added a motion sensor to the garage that turns on the lights automatically and turns off after 10 minutes of inactivity. The outside lights come on automatically at dusk and turn off at midnight.
I'm happy to answer any questions you might have, as I've been knee-deep in this stuff for months and have a lot of experience with it (and friends that have a ton of stuff installed that are tech junkies that I can ask, too).
Just to clarify, Matter is actually different from Zigbee. Zigbee is an older standard (like Z-Wave) and Zigbee is part of the working group that has been crafting the specifications for Matter. Yes, some of the tech that underlies Zigbee has become part of the Matter specification, but they are not the same.