What's the significance of using cartridges? Better load times and portability...

Even when recordable optical discs were first introduced to the consumer market, they were far cheaper to produce by bulk pressing than cartridges. You might have a point if you were comparing CDs to audio cassettes in the mid 80s, but there has never been a time that solid state memory was cheaper than pressing a reflective layer between two pieces of plastic.

When you are talking about that layer needing to be accurate within microns you will find it was cheaper to use solid state form the first consoles through to the early 90s.
You think the console manufactures hated money and wouldn't minimize costs where they could?

Silicone chips are made from multiple layers that need to be accurate not to microns but nanometers (1000 times smaller)

The limitation I believe in optical discs at the time was the laser and the optics to focus the laser.

Kill yourself.

You are comparing the chips of today with the manufacturing capability of 30 years ago, a time when the best intel CPUs smallest component was 1 micron.

If the smallest component is a micron then the manufacturing accuracy needs to be much smaller.

I guess we could say at the time CDs required 1 micron tolerance and silicone chips required 0.1 micron.

Either way people aren't going to pay the same for a game as they will for a top of the line CPU meaning cartridges were more economically viable at the time as they used older larger processes for their small slow storage chips.

ũber coolness, I can't explain it, I just like fingering and sniffing carts

can somebody tell me what is production price for catridges? and lets think how big switch cartridges will be, games on 3ds was up to 8 if im not wrong, on wii u i saw file up to 11 or 12 gb, how much space we need? if game devs are not retarded and ont make 99% of game size as flac media then 16/32 gb should be enaught, and then what will be price for even 64gb cartridge? and what is for blurey disc like that

Semi-related.
I think all media will go solid state in the next 10 years. Optical is getting too slow for the huge data transfer rates needed for 4k video.

Making an optical drive durable and cost effective on a semi-portable device is another factor. PSP models can run to problems with the hinge and all over time (not that most people notice anymore since almost everyone runshould ISOs via memory cards now)

The last handheld that had an optical disk was the PSP. The disk drive chewed through the battery and increased load times. If you had one with a weak hinge, twisting the handheld a bit (dumb, but there are people out there who spike controllers on bad days) could actually pop the disk right out of the drive. There's a reason why the Vita switched to cartridges and Nintendo never bothered with a handheld optical disk drive. The Switch would have even worse battery life than it'll probably have if they were dumb enough to use optical disks in it.

You know how you went from a HDD to an SSD for your rapid storage of stuff? Same reason.

The reason disks are slow is because the drive has to select the correct track on the disc to read it. Solid state storage doesn't have this.
If you take care of disks they last just fine, but you can be rougher with a cartridge. Buy a cartridge game used and it'll most likely work, but a badly kept game from the PS2/GCN/Xbox/DC era won't run properly. As a result resale value is usually higher.
Some games, such as Star Fox on the SNES, have extra hardware on the cart. Kirby Tilt and Tumble for the GBC and Warioware Twisted for the GBA had gyroscopes. Flashcarts tend to have MicroSD card slots in them. You can't extend a disc in the same way.
This is mostly for older cartridges, but you can flash or replace the EEPROM. People make reproduction carts of Mother 3 and Star Fox 2 like this. Not that much of an advantage, since you can burn a disc as well with the right hardware.
See every Pokemon game. Your console doesn't have to have the ability to store data, because the cartridges can do that. Most N64 games did this even though Memory Paks were a thing.
Vita game carts are around the size of SD cards. 3DS games are the size of a postage stamp. You can stuff your pocket full of vidya without a care.
See the Xbox 360.
There's no moving parts, so your cartridge makes no noise. Not that this is much of an issue unless you have a Dreamcast.

As for downsides
You can outsource disc production to many of the companies that do that. Game cartridges are usually custom, so you have to pay a premium The Neo Geo Gold X used SD cards but that was shit
See Resident Evil: Mercenaries on the 3DS. You can't wipe your save, so used copies are fucked.