They can't make it bigger because there isn't the material to do it.
You can relate it to the Eiffel Tower in Paris and the one in Las Vegas. The one in Vegas is half the size but otherwise the same. Could you use everything just within the Las Vegas structure to make it the same size as the one in Paris? Nope! That would be impossible.
Medical advances aren't as such that the material can just be added so they can only, essentially, elongate to where it is still effective. That's what they do with meta. What they do with phallo is use other tissue to create a more realistic size. But in doing this, that tissue is not the same as cis male spongy tissue and so to get that you sacrifice things like being able to get hard.
As for the ability to actually cum, I can't personally understand why that'd be necessary. Unless you could actually produce sperm, it's somewhat pointless to me to be able to do that.
Another thing to bare in mind is that sex is NOT like porn! In porn women can orgasm based only on penetration. That's a lie. The majority of women cannot orgasm on penetration on its own, they also require clitoral stimulation. And even at that, many will never orgasm during actual penetrative sex at all and this part of the act becomes merely for the men's pleasure. I'm trying to not get too graphic on a PG-13 forum, but women do need foreplay. For some women you'd need to basically pleasure them first and then finish on your own. For other women, it might be easier. And others it may even be possible with other sex aids. This is stuff all guys have to deal with but again, not something they'll openly talk about because the lie men like to tell themselves (and the cocky ones tell others) is that they have big dicks and easily satisfy their women.
The point is, size is more a male concern or a shallow woman's. If we're going to be fair, maybe a more lucky woman who can orgasm more readily with penetrative sex. Most women actually find a bigger penis stimulating sexually, but are actually afraid to have one inside them. Guys with a bigger penis have actually been known to get reductions because they struggle to find anyone that is willing to try their size, or if they do, be able to actually take it!
Being more sensitive and intimate with a woman goes a lot further than having a big dick. And I think you're getting ahead of yourself worrying about this stuff. You don't know what your growth will be yet. You don't know what your financial situation will be in the future with regards to worrying about surgery. I'm assuming you haven't had any sexual experiences yet either, so my advice would be to slow down and try and get with the now than worry about the many, many, many years from now.
I think this applies to everyone, if a partner only likes you for sex. If you have any self respect, you get out of that relationship. Relationships are NOT about sex. If someone sees your dick and laughs at it, you either close the door or step up to the challenge and show that you more than make up for it. Make them apologise for that laugh and some!
Here's what the right partner doesn't worry about: size and cum (actually, many women hate the latter).
Here's what the wrong partner worries about: size and cum.
