The first gen consumer led bulns were great; big heat sinks and, except for infant mortality, very, very long lived. Frustratingly, your new ones won't be....
We had 2700k in our kitchen, but after changing the cabinets to grey, went to GE Refresh 5000k, bright and just shy of harsh.
Depends on the design. Most Edison-base bulbs are designed with a compact array that more or less spreads out, but from a central point. That can clearly get hot. I’ve had a few fail and clearly they had no heat sink as that would have cost more than I paid for it. Newer designs in fixtures avoid concentrating the LEDs. The fixtures I previously mentioned had a checkerboard pattern. I took apart a failing direct wire fluorescent tube replacement (replaced under warranty) and found that the the lights were really just a strip of LEDs. The electronics were solid, but the problem was mechanical, where the contact from the pins to the power supply was marginal. They kind of spun around and the pins didn’t make good contact with the socket.
I remember a few years back there was a company called iWatt whose primary product was a digital LED light controller. I wasn’t sure exactly what their value proposition was as they were extremely expensive parts. They were supposed to provide maximum efficiency and life, but’s it’s hard to compete with dollar store prices. I think one of their claims was that with their control, a heat sink wasn’t necessary.