Its always weird to me when people use U Le Guin as an example of "optimistic" sci fi. Some of her writing is extremely bleak. Of course she is pretty prolific and has written a lot of different types of things.
Fundamentally i think the issue is that novels usually have to be about conflict. If everything is peachy you dont have a novel. I think it takes much more skill to write an interesting optimistic near future sci fi novel that is actually about the technical change instead of just using it as a setting.
Most of the optimistic technology novels i can think of that i liked were far future - Iain banks. Maybe greg egan although optimistic isnt exactly the right word. They show an interesting world, but its clearly not our world. Is it really an optimistic take on the future of technology if the technology in question is hundreds of years in the future?
Perhaps you'd like something like "Song for a new day" by Sarah Pinsker.
I dont really know if it fits as "optimism", but i'd like to mention "The Fortunate Fall" as a really interesting novel about technology.