What kind of performance benefits can I expect from going from a - decent - hybrid bike to a road?

I got into cycling during the pandemic. I was about 60 pounds overweight and needed to get into a cardio exercise that I could enjoy. Suffice to say, cycling more than scratched that itch.

I went with a hybrid bike as im primarily using it in London, but have recently started going out on 80km+ rides and have been wondering whether the switch to road is worth it.

My current bike is a Specialized Sirius 4.0 (don’t think this place lets me post links, but it’s the 2020 model, the one with bull horns and an aluminium/carbon frame and 700x32c tires). When I bought it, guy in the store said it was essentially a road bike with flat bars.

It’s performed very well for me over the years, but I’m now wondering whether I should ‘upgrade’ to a roadie.

What kind of performance benefits can I expect from doing this? Would it be a substantial increase in km/h, for instance? I’m averaging 24km/h on my morning commute, but thinking over longer distances, would the impact be noticeable?

Or would I better looking at upgrading the Specialized? Maybe changing to thinner wheels? I do like the flat bar and bullhorn option.

Any advice from those in the know or who have done similar would be much appreciated.

Thanks