You're conflating the consequences of modern and ancient inflation, which were extremely different. In modern times when we want to print money, it just involves a mixture of worthless sheets of paper or even more worthless entries in a database. So we have the luxury of being able to just pull trillions of dollars out of thin air, devaluing all of the other preexisting dollars in the process.
But in the past, money was made of materials that themselves had major value - like silver. And so you couldn't just print more money, because you had to have the valuable resources that it was made of to do so. So the way the Empire dealt with this was by simply reducing the percent of those values. Wiki has a table showing the composition of the Roman Denarius over time here. [1] The original denarius, from the 3rd century BC was 95%+ pure silver. By the 3rd century AD it was down to 5% silver. So the process of printing money in ancient times, ended up making the old money worth more, which is the exact opposite of what happens now a days!
A good analog here is the US penny. We've been debasing it over time, but all the way up until 1982, the penny was made with at least 95% copper. [2] So old pennies are actually worth more than $0.01 in raw materials, which is why it's currently illegal to melt pennies (and nickels) or sell them for their material value. So there are plenty of people hoarding these, waiting for the government to eventually declare them obsolete - enabling them to melt them down and make a large profit. It's a nice investment because your upside is uncapped and your max loss is $0, if you can get them at around the fiat rate.
Now imagine if 225 pennies was a year's salary, as was the case for e.g. Julius Caesar's professional soldiers and Denarii. It creates a huge motivation for hooooold, precisely caused by the government spending. Same today where the more we inflate the currency, the more old pennies become worth.
[1] - https://en.wikipedia.org/wiki/Denarius#Value,_comparisons_an...
[2] - https://en.wikipedia.org/wiki/Penny_(United_States_coin)#His...