555 Timer Circuits

Built many a 555 timer circuit back in the day! But in modern times, I can get an ATMega328p already attached to a PC board for $2.50 and load code on it to do whatever I want, including blink a red LED.

Not only are cheap microcontrollers often an easier choice for things the NE555 might be used for, they often draw far less power as well. I personally prefer to use an even smaller and cheaper micro like the ATTiny13A. It's also worth noting that your traditional 555 timers don't like to run below 5V, for that you'll need something like an LMC555. If you're building up a parts inventory, it often makes sense to have a bunch of very cheap micros rather than special purpose parts.

The main advantage of 555 timer is that it is configured with a resistor/capacitor kit. No computer or programming required.

Microcontrollers obviously have more than 1 bit of memory + 2x analog comparators + one 33% / 66% voltage divider (which is all a 555 timer truly is).

What is surprising however is how flexible 1 bit of memory + 2x analog comparators + one 33% / 66% voltage divider

Except, it's not an advantage in any practical sense. Programmers cost pennies, toolchains are free and easy to use, and there are ample examples for simple tasks such as "toggle a pin in a particular way". The overall learning curve is almost certainly less steep than the learning curve for all the modes and quirks of the 555.

What matters in production is that a 555-based circuit will use more power, that it's four components to source and install instead of one, and so on. Don't get me wrong, I like the 555, just like I like vacuum tubes, but it's nearly as dead.