That's just the UK. That's not a global perception of nuclear.
You run out of space for renewables and they have negative impacts for the environment, even if they've improved they still are more impactful than Nuclear. Being cheaper isn't really a thing either. The vast amount of renewables you would need to output the same power as one reactor means despite being cheaper you end up spending more money and taking up more space which means less area to inhabit which further means less tax money to obtain from the government. The nuclear costs goes into initial construction. Once that's done it's low maintenance with a handful of experts operating the plant.
Also by investing more money into nuclear, we eventually will get closer to Fusion based plants, which will far supersede anything ever made with almost an infinite 0 possibility of failure. It's the perfect source of energy.
For wind and tidal here, very little land is actually required as pretty much all generation occurs off-shore, in the sea.
Each of these wind farms will have power generation levels around that of our currently operating nuclear power plants
Again I can only speak for the UK, but two quite comparable projects in terms of being "expensive firsts", East Anglia Array is expected to cost £2.5 Bn for 7GW, our next reactor Hinkley Point C will cost at least £23 Bn in construction alone for 3.2GW. That's ~x10 more expensive for roughly half the peak power generation, ofc average power generation levels would be quite close. It's become a pretty large overall cost gap that is only set to grow with time.
Disagree on the point about investing in companies specialised in Nuclear fission helping Fusion though, currently the only way to progress with Fusion is for governments to invest in the universities and research institutions researching Fusion, traditional energy and engineering companies developing Nuclear tech at the moment are busy spending the vast majority of their money going in completely different directions, with a lot of focus now on developing smaller, modular reactors, with ample fail-safes, making use of Thorium, the revival of MSRs, ect. Many of these companies still view fission tech as having at least a century of life left through safety developments and are in no rush to start considering experimental fusion reactors that are still very much the domain of physicists and not engineers, because they believe we are still decades away from that being profitable. There's a lot of other potential use cases for small, safe nuclear reactors, and some nations would never be able to make good use of renewables, so its not cut and dry.
But for the UK govt., renewables is a way to significantly reduce costs, not just against Nuclear, but here renewables are also far cheaper than the gas fired power stations that meet a lot of our rapid demand changes currently, and cheaper than continually mothballing and reviving coal power stations with imported coal from China as needed.