We often hear that Bitcoin gives us financial freedom
Freedom doesn't exist - including "financial" freedom. For on the other side of that freedom lies responsibility (dependence and obligations). In the realm of finance, this entails ensuring the safe and secure custody of assets.
and theWhat if Satoshi Nakamoto decided to build his own Bitcoin exchange and hardware wallet?
You are proceeding from the assumption that if Satoshi managed to create bitcoin, he would surely be able to create the perfect exchange and "hardware wallet as well? You are idealizing the situation. No matter how brilliant a single individual may be, a group of people will manage to outperform them in terms of results.
Would that make Bitcoin safer, or would it create another problem?
Taking on external tasks (such as creating an exchange and HW device )would have diverted Satoshi's resources; this almost certainly would have been detrimental to the development of bitcoin (due to fewer resources being allocated to it) and could have resulted in the asset being "worse" than it is today.
However, when it comes to buying and securing Bitcoin, many of us still depend on third party services.
No one is forcing you to use exchanges or hardware wallets to store your assets. After all, you can create (develop) such a service yourself.

We buy Bitcoin on exchanges, leave some of our funds on those platforms,
Don't say "we."

The majority here on this forum would vehemently disagree with you.
and purchase hardware wallets from manufacturers to protect our private keys.
Until recently, this was a rational move. But times change, and a moment arrives when new asset protection methods are required. For malicious actors don't sit idle; they seek out vulnerabilities and ways to break in (with AI).
The recent large attacks on bitcoin from ColdCard Hardware Wallet to the most recent which is Ledger Hardware Wallets and Cryptobilis and many other exchanges that have been compromised got me thinking "What if Satoshi Nakamoto decided to build his own Bitcoin exchange and hardware wallet? Would that make Bitcoin safer, or would it create another problem?"
Satoshi is not God, capable of creating everything perfectly. Just because someone has succeeded in one area doesn't mean he would succeed in other endeavors or projects. Besides, why speculate when he isn't with us (and can't create either a perfect exchange or a hardware wallet)?
By the way, have you ever wondered if Satoshi would even want to do this (exchanges and HWallets)? That is, after all, the most important question.
If Satoshi (this is hypothetical i am just thinking aloud) decides to create an exchange or a hardware wallet would you use it?
Just because
He created it?
For me i would definitely use it because the originator of this magnificent currency would definitely know how best to protect it.
But what if that’s not the case?

You’ve created an idol for yourself and believe that everything he "touches" turns to gold. Maybe it’s time to grow up a little?

I understand that for you and many others, Satoshi is a
Hero, but there is no need to let your imagination run wild; should look at things realistically.
Furthermore, given that the
BTC-community continues to develop and improve bitcoin, it follows that bitcoin was not created perfectly.