You really have to qualify the different aspects of the generation to evaluate it:
Hardware: Best=PS5 | Worst=PS3: PS5 HW is easily Sony's best in terms of design, balance, capability, feature set, and developer usability. (i.e. DualSense is easily Sony's best controller and adding SSD, Ray Tracing, and 3D audio standard are really impactful features that were well implemented)
First Party Games: Best=PS2 | Worst=PS5: This is where the PS5 generation clearly fails. First party output has been anemic in terms of quantity and quality (too many remasters, most studios haven't released a single game after over 4 years)
General Software Quality: Best=PS2 | Worst=PS3: I'd say PS3 had lower overall quality of SW due to the poor performance for many 3rd party releases that generation. Also, the controller was the worst of all PS generations which affected the enjoyment of some titles.
Game Performance: Best=PS5 | Worst=PS3: PS5 generation has had by far the best performance where >95% of all releases run at 60fps. Not only that but the consistency of the performance is superior to prior generations due to the balanced design.
Overall, every PlayStation generation has had some merit but I wouldn't consider the PS5 the worst generation. The HW itself is a masterclass of console design with no aspect of the system not addressed (controller, input, storage, audio, graphics, HDMI etc) and superb balance all around. The issue this generation is more about software, economics, and developer priorities/capabilities. This is affecting Microsoft and Nintendo as well. That said, Sony's first party has been a huge disappointment this gen and the studios have been horribly mismanaged in terms of the titles they were developing. Luckily, Sony has had meaningful third parties alliances to take up the slack in many instances. Not to say that Sony first party has not delivered great games. Arguably the best games this gen so far has come from Sony first party including Returnal, Helldivers 2, Astro Bot, Horizon Forbidden West, SpiderMan 2, and Rift Apart. Hopefully we'll still get at least once true PS5 gen title from Sony's studios before the gen is over (GT8, Next Santa Monica game, Wolverine, Intergalactic, etc)