We live in a dangerous world. We cannot control everything. I don't mind a slight risk of terrorist attack on myself or my family (caveat lector: I am young), if that means greater freedom.
In my book this is the first step towards authoritarianism: ensure that the state survives at all costs. And being able to spy on the whole population to track outlaws and dissidents is part of this. There is an invisible barrier between what's legal and what's not. Crossing it isn't hard, look at extinction rebellion and other civil disobedience protestors. Yet, on the other side, your trusted options are very limited, and encryption is one of those. I'd argue that letting citizens communicate and organize privately is a vital component of democracy, even allowing citizens to seize control of the state if they deem it necessary. More so than U.S.A.'s "Second amendment", encryption is an arm citizens should legally be able to bear.
Now, it is obviously hypocritical to offer such a thing, as politicians certainly wouldn't want their texts to be snooped on, would they? Any bill that requests backdoors should request them from everyone.
And don't get me started on how governments recommend their own to use Matrix and Signal, the very apps they aim to backdoor, because they are secure. You can't both have your cake and eat it, too.
A useful thing to explain encryption backdoors is the TSA master keys: https://news.ycombinator.com/item?id=12177079
Their very existence made locks less secure (possibility of a key leak), and those are worthless against thieves now that master keys have leaked (you can 3D print them).