It can boost the economy. Money is one of the factors of production, and also the most important factor in economic growth and development; the corona virus pandemic created a situation were money became scarce for citizens and their businesses also due to lockdown and other restrictions, stimulus bonuses can reactivate the economy my providing funds for individuals, so they will in turn patronize other businesses that fits their taste, business men and women can also channel the funds to growing their businesses again, the checks are given to stimulate citizens, so they'll in turn stimulate the economy; the only downside of this is the possibility of inflation in years to come.
The U.S printing money for stimulus packages can't affect the price of bitcoin, only if you look at a scenario where majority of citizens buy bitcoins to evade the inflation of their currency, that is then more demand and a price appreciation to follow.