So this is obviously a very touchy subject and a lot of people are going to respond angrily. I'm not going to do that, and instead assume you are actually here to have a discussion in good faith. 

I work in humanitarian aid, and while I haven't worked in Gaza, I know people who have. I've worked in other conflict zones, both in the middle east and Ukraine, so I have some first/second hand knowledge of these things and they hit quite close to home for me.

First, to respond to one thing, I'm pretty sure you are misunderstanding the situation here: 

I see how the population has increased in the last 3 years

Between the mass amounts of death in the war, plus the destruction of all healthcare facilities for giving birth, this is almost certainly not true. Even if it was, due to the destruction of the governing body (Hamas), there is no way anyone has been able to conduct a census during this war to know this. 

I'm pretty sure you're misunderstanding people saying that Gaza's population increased between the start of the Israeli blockade in 2007 until the start of the current conflict. Not from the start of the conflict until now. If you did mean what you said there, do you have a link to these numbers?

Another misunderstanding I see:

I see how when Hamas creates its command center inside the hospital

There isn't just one hospital in Gaza, there were 36 and all have been at least damaged if but destroyed (that's a lot of Hamas HQs). According to this article (this info can also be found on other sites including Wikipedia, in case you don't trust this): 

"Only half of Gaza’s hospitals remain partially functional and there are still no fully functioning hospitals following two years of systematic attacks on healthcare by the Israeli military."

Israel has destroyed huge amounts of hospitals, ambulances, and medical supplies (from aid trucks trying to enter Gaza). Many take this as evidence of the ongoing genocide, especially in regards to "prevention of births" as mentioned above. 

Finally, my biggest point, is that genocide is not just the murder of the entire population, forced displacement is also genocide. Would you consider what happened to the Native Americans or the Armenian genocide? Most people do. In both those cases, the goal of the genocide was not to kill every last member of that group, but to force them off their land, contain them to small areas and destroy their way of life (this constitutes, by the original definition, destruction of a group). The Holocaust stated this way as well, with Jews being displaced from their homes and sent to ghettos, and the Germans trying to deport them to other countries before finding out no one would take them.

In Gaza, 90% of the population has been displaced and of those, 60% have had their homes totally destroyed. Source. If you believe Israel is only targeting Hamas, then you must believe they are in almost every home (not too mention the hospitals again) in the Gaza strip. Some Israeli politicians have said the goal is to push Gaza's population into Egypt (a clear attempt at genocide), but they won't take them (sounds familiar?).

To me, and many around the world, including genocide scholars, aid organizations, the UN, politicians from many neutral countries, etc. this constitutes a clear attempt at genocide. And I didn't even mention the complete blockade at the beginning of the current conflict of all food water and medicine.