That's an understatement. With the usual caveats that benchmarks lie and all that, here's a pretty fast server I had in 2008 or so vs a modern iPhone[0]. The single core scores are 430 and 3427 respectively, and multi-core scores are 745 vs 8494. The phone wipes the floor with the server on normal tasks. On things that use huge amounts of FLOPS like object detection, it's just about 100x faster.
In addition, the entire A18 SoC uses around 10W max, vs the E8400 burning 65W by itself.
If you want to go back to exactly 20 years ago, there's a Pentium 4 vs an iPhone.[1] It had single/multi-core performance of 185/216 at 85W (by itself, not including chipset and RAM), and the phone runs math stuff around 500x faster.
Yes. Your smartphone is many times faster than most computers of that era.
[0] https://browser.geekbench.com/v6/cpu/compare/12190780?baseli...
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