As a ceiling? No absolutely not. There are some niche cases, but usually not at consumer level (perhaps a high TDP CPU, paired with the highest wattage GPU, with some excessive open-loop cooling could warrant it, and maybe throw in some novelty Molex Edison lightbulbs could warrant it).

https://www.coolermaster.com/en-global/guide-and-resources/what-is-80-plus-efficiency/

Remember that PSUs run most efficiently at about 50% load. In other words, a 1200W PSU most efficiently serves a system running at 600W load. Unfortunately, it's not as simple as "just buy 2x."

Most consumers PSUs aren't running at 100% load constantly (aside from perhaps mining rigs/AI/rendering stations). Usually it's a mix of work, browsing, other hobbies, and frame-capped/limited games (idle load is typically <60-80W, about the same as an incandescent lightbulb).

Remember that PSU rating is power efficiency and not necessarily quality (though it often correlates as long as the manufacturer is being honest about their certification). So if you're buying a Titanium efficiency PSU for the purpose of the certification, you're buying it for its power efficiency. If you're only running at max load (600W) at 50% efficiency for a few hours on the weekends, you're talking a 4% difference in efficiency from a gold.

Going to do a bit of sloppy math (technically this answer will be a bit lowballed because I'm lazy and my starting point for Titanium is 100% efficiency). In the US, a 600 watts running for an hour averages about $0.11 (at the high end it can be double that). 4% of that is a fraction of a penny per hour. There are 8760 hours in a year, so if we run that device all year at a 600W load that a total of about $963; but we're only looking at the cost due to a 4% lower efficiency.. 4% of that is $38. Given that many Titanium PSUs have 10 year warranties.. a 600W load running 4% more efficiently over 10 years could be about $380 in savings over that period (it should be a little more).

Great if you're constantly running at load or in a fleet in somewhere like a data center.. but most consumers probably wont be. Even when they're gaming, most will be running at only partial load - especially if they're framelimiting to their monitor specs.

The cheapest titanium 1000W I see on Newegg is about $200. I know I paid $80 for my 850W Gold. Technically, I can't directly compare because my max system load is nowhere near 600W.. but for oversimplified math.. to make up for the $120 additional cost and break even from a 4% efficiency difference @ a 600W load, if my math is correct you'd need need to run it at full load for 7.5 hours a day for 10 years. That's just to break even and not get into the "saving money". Again, my ceiling was $380 with average US energy prices. In markets that are more expensive (like California/Hawaii) that could double. In other countries, it could be even more significant. But unfortunately, we do kind of arrive at the point where if it's a lot of money to the consumer.. they probably don't have a 600W load build and thus that break even gets even harder to justify.