Also some forms of shapeshifting can be horrifying. In some kinds of shapeshifting, you have to be able to visualize every minute detail of the form you're shifting into. Imagine getting shapeshifting powers and shifting into another form. Then when you want to shift back, you realize you don't actually have a "default form." You can shift forms as often as you want, but you have to picture and visualize every minute detail. Your original form is now lost forever. Remember Odo from Deep Space 9? His form was roughly humanoid but clearly not natural. He had to consciously control every minute detail of his face.

Imagine trying to paint a photo-realistic painting of yourself. That's a fraction of the level of detail you'll need to capture every detail of the forms you're changing into, including your original one. Even your original form is now lost, replaced with whatever half-remembered remnant you can cobble together with your mind.

Just shapeshift into someone with other powers

Also I'm repping my ancestors. It's a proud heritage

It's not actually shapeshifting you just perfectly transform everyone's perception including yourselves to appear as such. There, no more physics breaking.

Magic.

I always liked the powers from chronicle.

If you've read Watchmen you know what the downside of that power is. Godlike power leads to detachment from the human race. You lose the connection to everything you ever loved, to your humanity.

The worst that being a shapeshifter will do to you is getting you into some kinky sex.

What did I pick?

Russia.

So I don't risk fucking up thermodynamics next time I drop acid and making atoms stop being a thing.

Think through the state of the world and the consequences of those things. Unless you're also invincible you will be killed for doing literally any of those things.

Lets just do world hunger. We produce around 2.5x the amount of food needed to feed everyone to the average american caloric intake. That's something we already do. We have the ability to ship any good anywhere in the world within 12 hours, or alternatively, keep a good fresh enough to be sold over MONTHS of transportation (think the fresh fruits picked in South America that is shipped to Thailand to be processed and shipped to china to be packaged then shipped to the US to be sold 3-6 months after they were picked.).

We have no world hunger. There is not a lack of food. There is not a lack of transportation.

Hunger is used as a weapon. Period. That is the totality of the reason that any single person or group of people do not have the ability eat 3 square meals a day.

If you, as (presumably) an American were to just bring food to Cuba, you will be investigated by congress and Trump's DOJ both on criminal charges. (see Hasan Piker currently being subpeanoaed for just filming Cubans and bringing food.)

If you magically could produce infinite food, you have just taken away the most used weapon in world history. This means you are the single most hated and despised person by not only those in power, by but everyone that benefits from those in power, and that's a lot of people, and they own (effectively) all the guns and nukes.

The reason people dream small with superpowers is because, realistically, as long as you don't drastically change the status quo, you're safe.

That's what CYOA's are for, they are the complete game that this question teases but never delivers.

My favourite is https://cyoa.ltouroumov.ch/viewer/

I've spent hours of my life, every single day, just browsing its insanely long list of powers and trying to make various combos and synergies.

Omnipotence also needs to have rules. What if it doesn't come with omniscience? What if your powers are so immense that they're utterly impossible to control? You move the muscles you'd normally use to stand up, and your power shoots through your legs, shattering the planet.