I have a lot of bulbs. Right now I have 44 and grew to that many over 12 months.
I have a lot of experience with problems the volume of lights have cause and how I solved it.
I won't tell you the whole story as it is very long, I'll just tell you what I do now. If you have any questions I'd gladly answer.
Let me start with explaining how many network clients I have, wireless and wired. This is important because I ran into issues with both number of wireless clients (which others have experienced) and just total number of network devices.
I currently have...
44 LIFX Bulbs (Mostly BR30 Color 1000s Gen2)
~80 total wireless clients (~55 are 2.4ghz, rest are 5ghz) *note the bulbs are 2.4ghz only.
120 total network clients with an IP.
The first issue I ran into was my wireless router could not handle 45+ or so wireless clients well. They all stayed connected, however the lights basically became 50/50 as to if they would respond.
Keeping the same router, I purchased 2 Ubiquiti UAP AC PRO access points and a Ubiquiti Cloud key. I kept the same router. After installing these access points and spending some tweaking the config I got my lights to basically 100% reliability.
As I got more lights and other wireless and wired devices I learned that my router was struggling to route traffic for 70+ devices (wired or wireless).
I switched to the Ubiquiti EdgeRouter and my problems cleared up.
I continued to add more wireless devices and found that even Ubiquiti had trouble with 40+ devices per AP. So I got a few more APs. My devices are balanced across the APs based on location in my home and no AP has more than 35 devices.
You ask if it is bulb issue or just standard networking issues, I'd say both. It is clear my networking equipment couldn't handle everything until I upgraded / expanded. That said, these bulbs and the LIFX code does have issues. I feel like the bulbs could recover better when losing a connection.
As for HTTP vs LAN... I will tell you that my LAN control is useless. It never works right. Right now if I was to do a LAN request to turn off all of my lights (using the LIFX app) at once only 30-50% would turn off. If I disable wifi and use my cellular connection 100% would turn off.
I should also tell you that I am a SmartThings users. I control these lights mainly with automations versus wall switches / mobile apps.
Let me know what specifics you want.