Create time counter with display with capacity for several hours
You can certainly do that with discrete logic, an 555 for the second timer, and discrete 7-segment display drivers.

That will take dozens of components, hours to build, and will have pretty terrible accuracy. 

Or, you can buy a cheap microcontroler board (e.g. a small Arduino-compatible board, or anything else), and do it in half an hour.

That will be significantly easier, and add a much more practical skill to your repertoire. Also, it might use far less power (the classical 555 isn't power-efficient at all, and with a microcontroller, you could also easily dim the displays, so that you can save even more power).



Personally, I see the 555 as an excellent example circuit for simple analog oscillation generators, and something that you can wire up at least once in your live to make something blink, or listen to a ca. 1 kHz square wave.

It should be used as an example for simple circuitry, that's all. 

There's some legitimate usage, especially when dealing with a simple-to-define behaviour, see Finbarr's comment below, but I'd argue that for applications where you'd need to process your 555's output in a complicated way, a microcontroller will get the job done much much easier, and usually, more cost-effectively.