A lot of manufacturers have parts designed as drop in replacements for older parts, sometimes even with similar looking part numbers. Another thing that I often

A lot of manufacturers have parts designed as drop in replacements for older parts, sometimes even with similar looking part numbers. Another thing that I often do is use Digikey's search and check their stock quantity to find out what's "popular". For example, if I want an op amp, I'll go to that category on Digikey and then first enter a quantity and sort by price. Then I'll start adding constraints - for example, for a 324 replacement, I might want it to be through hole (I nearly always do SMD designs though). From that, I unsurprisingly find the LM324 (it's still one of the cheapest!). But I also find the MCP6002, which is lower voltage but has rail to rail inputs and is designed for a capacitive load - perfect for driving a microcontroller ADC. The truth though is that it's not like the old parts got any worse, and are still often the cheapest choice. You have to add additional constraints (I want lower loss, better performance etc) for something else to be "better".