Sadly, that's far from truth...
"back in the day", you had an ericsson charger that fit in an ericsson phone and charget that ericsson phone well... and you had a nokia charger for you nokia that charged your nokia. They physically looked different, they wouldn't fit into any other device, and when you needed a charger, you'd take the one that fit the charging hole and it would charge.
Now, you have a bunch of usb C bricks, some just 5V usb, some USB PD, some QC(2, 3).... then you have a bunch of usb C cables, some with ID chips, some without, some able to carry 15 watts, some 100 watts, and then you have devices, some that can do QC, some that can do smart PD, some with just some resistors, some without even those.
Everything fits in every hole, every charger can take any cable and any device can take the other end of the cable.... but will this particular combo charge your laptop? The cable fits.. will it charge? What about those cheap earbuds that just want 5 volts? The USB-A to usb-C cable that came with them works, but the USB-C to USB-C that you bought after, doesn't. How about that smart LiPo charger, it's USB-C, but it needs at least 9 volts to charge, and not every power brick gives out that voltage. What about charging speed? Will it do fast charge? Your laptop charging light is on, but the battery percentage is going down... why? What about a powerbank, does it charge your laptop? How does it know who does the charging, and who is getting charged?
I mean sure, if you know your standards, you'll know what devices need PD and which ones use QC, you'll read the specs on the power bricks, you know how many watts your laptop needs, how to switch the current directions, which devices can't do proper handshakes, and need usbA->C cables, etc, and you'll get yourself a baggie of a few power bricks and cables for different stuff, but i had to label the cables for my mom, because while everything physically fits, many combinations won't actually charge your device. 10 years ago, this wasn't a problem, since her laptop charger didn't fit her wireless earphones, now it fits and it doesn't charge them.
In practice, this complexity means you at least have a chance. Most phones and almost all low-power devices will accept power from most chargers and cables. Probably not at a maximum level, but if you're stuck somewhere you can get by.
Power-hungry laptops are trickier, but even so... I've gone a week or more trickle charging a laptop from whatever travel charger I happened to have on hand, using it for a few hours, then putting it in standby and charging it up again until finally the mfg-blessed replacement fast charger arrived. The alternative (and one I was faced with more than once in the bad old days) was "no laptop".
Worst experience I've had to date has been a Norco jump box that will charge via one high-power charger and one cable, a car charger it came with, and ... Via careful back feeding from a benchtop power supply.
I have successfully had am M1 MacBook open and in active use (albeit not with very heavy workload, mostly text editor and web), while plugged into a Nintendo Switch 1 charger (only thing I had handy at that moment), and was watching the battery percentage slowly increasing over time. So even laptops can sometimes charge slowly while in use with a rather underpowered type C charger (Albeit still slightly better than a cheapo 5V 3A Type-C phone charger).
I've charged a Mac with the Switch cable, and a Switch with the Mac brick. Nowadays I charge everything with the same brick from a dell laptop from 2018.
Is it the most efficient? Probably not. Is it hurting the batteries of my devices? I guess?? I haven't noticed any issues with any device and that's 8 years now. Perhaps I've been lucky.
That's for charging. Data can be trickier, that's true, but often devices that use USB-C for serious stuff come with their own. Chargers from aliexpress-grade stuff I just discard to the drawer of the 1M-cables from where nothing will ever come out.
You may be right, and I've had to live some of that myself with docking stations, thunderbolt, and such.
But those moments are the exceptions. In my everyday life, when I need to charge _anything_, except maybe for the laptop itself, I just look for a charger with USB-C and it works. It maybe faster or slower depending on everything you just wrote, but it works.
On a side-note, when I take the charger of my laptop, it can charge absolutely everything.
So yes, that's a true and honest improvement.
Yep, we gained nothing from moving laptops and other high power devices into USB, instead of finishing the standardization of the barrel connector. Laptops chargers were already almost all compatible, and there is no reason to mix them with the low power devices.