There are some people who dispute this. They tell us we cannot have nice things.
There are religious people, many of whom claim that God doesn't want you to have particular nice things, or even any nice things. Sometimes, they promise you nice things later on in exchange, but tell us to take their word on that.
There are the ascetics and the moralists, who think that nice things distract one from the true path.
There are the socialists, who think nice things are created regardless of incentives. There are the victims of akrasia, the lazy, and others who think that nice things should happen and be shared with them, without their help.
There are the egalitarians, who think that if you didn't bring enough nice things for the whole class, then you can't have them either.
There are the advocates of social justice, who won't let you have nice things unless everyone is happy with every element of them, and trade would be cheating.
There are the regulators, who think nice things are against the rules.
There are the central planners, who direct all the things however they think is best, usually destroying most of them in the process.
There are the thieves and murderers, who think that they want your nice things, so they're going to take them.
Then of course there are the oligarchs, whose most important goal in life to make sure no one has nice things but them and their children. There are the status seekers, who want more nice things than you and don't much about the absolute numbers. There are those who think that if you have nice things, it means that they don't and are losing, and that can be fixed by destroying the nice things, after which they win. Mostly, of course, there are those who simply don't care at all about nice things that aren't theirs, or plan for the future, and ruthlessly turn to extracting what nice things they can, for themselves, no matter the consequences.
Know thine enemy. Know thyself.