I've fallen down the Rabbit Hole of liking light and fast (and interesting) bikes.
Not that I'm particularly fast.
I do have my old Colnago Super from decades back, and I do like it.
But, the Carbon Fiber Colnago C40 is a SWEET RIDE!!!
Ok, so eventually I might upgrade to something actually new.
Well, not quite new.
Last summer I met a guy, about 75 or so, with his ultralight CF bike. He lived at the top of a fairly steep hill, and the lightweight bike was a big plus.
Some of your choices will be dictated by the environment you're living in.
Hills, flats, short rides, long rides, fast, slow, cargo, etc.
For "new" bikes, you might look at the Specialized Roubaix. It is supposed to be designed with flex where one wants it, and strong where it is needed.
Another thing.
I still like my skinny tires, but there is some emphasis on somewhat larger more cushy tires.
At least the "cheap" tires seem to have a bit more rolling resistance, but that doesn't necessarily hold true for all, with some claiming that the quality wider tires have close to the same efficiency in the casual road riding range (10 to 20 MPH) as the narrow tires. 28mm? 32mm? 35mm? And, they give a more comfortable ride, in theory.