Boy am I envious. It took a lot more birthdays before
I was given permission to buy an A7Riv
Having said that I've had an A7 Rii for a few years and other Sony's before that.
As a. good walk around lens, and for most landscape work the 24-70 f2.8 GM is a great lens. It does cost a lot (although it sounds like its a lot less than I paid for mine a few years ago). Tamron has a similar lens, also f2.8 and with good reviews for less money than the sony. Some friends in the local camera club have the 24-105 f4 G lens and swear by it.
I've heard the sigma equivalent is also good but I had another sigma lens, in a different focal length, some years ago and I was quite disappointed with it.
A wide angle lens like the 16-35 is good for landscape and I would like the f2.8 GM in this range as well but I've had the 16-35mm F4 Zeiss OSS Lens for many years and I can't justify replacing it as it does everything I want it to do and my preferred genre is Landscape.
If you only have the 24-70 and want to do pano shots you can do a 2 shot stitch in Lightroom or photoshop. There'll be a thread on this forum about that.
My 70-200f2.8 is a Tamron that I've had for so long its actually an old A mount lens with an adaptor to the e mount system. A lovely lens, without in lens stabilisation, but it is a bit slow to autofocus but I think that's because of the adaptor - the next lens I'd like to get is the new Tamron 70-180 e mount.
I hope that helps a bit.