If future dollars are worth more, then it reduces motivation to lend and invest.
Not all lending and investing are good. We recently had a global economic collapse due to overly-incentivized lending and investing.
At the same time, it also makes it harder for debtors to repay their debts as their income streams are reducing. The net effect is that economic growth is hampered.
Their income streams aren't reducing. They are reducing when denominated in the deflating currency, but their real value is not reducing.
However, this just begs the question that constant growth is a good paradigm. I submit that it is not and instead what we need is an economy at equilibrium. Constant expansion has lead to us using up the resources of the planet and possibly already has us on a trajectory that will result in wide spread famine and loss. Part of the problem is the expansionary money system that makes it appear that we can just add new aspects to the economy without negative effects. An economy at equilibrium that readjusts when new real innovations are introduced is better equipped to handle the issues of a world with a finite limit of power input, finite water supply, and other resource limitations.
I don't agree. Resource limitations are fictional. If you don't see why, ask yourself this question -- was Uranium a resource in 1790? If not, then resources are not fixed and constant expansion includes resource expansion. If so, then the entire universe is a resource.