Any recent courses or content?

Used to buy a bunch of domains either based on custom multi-keyword algorithm, dropped domains (back in the day when there was less competition and dropped domains weren't auto-scooped), and flipping 4 and 5-letter domains (buy high, sell higher).

But haven't had much luck recently and existing inventory isn't moving or am getting lowball offers only. I admit I'm super casual about it last few years, but was thinking of getting back in. Are the glory days gone, or do I need to learn new skillz (probably both)?

Competition has increased a lot in this field. People using tools to book good domains in bulk.