I love the irony of claiming the left has a "monopoly" on information when Fox News dominated cable TV ratings up until this year, when the Capitol riot and Trump's exit tanked viewership.
For that matter, there are still plenty of conservatives on Facebook, Twitter, and other internet properties.
The talking heads that tell you the left has a monopoly on the media... they're lying to you. Conservatives have plenty of outlets on TV and in social media. It's just that misinformation and hate speech are disproportionately more likely to come from the right, so it 'feels' unfair.
I remember this great Twitter post (I wish I could find it easily) that summed up the real reason conservatives feel silenced online. I'll paraphrase:
Me: "Conservatives are being silenced, you say... so, you're being oppressed because you talk about small government and lower taxes?"
Conservatives: "No."
M: "Oh, so it's because you've spoken up about a strong military? Hawkish foreign policy? Looser regulations? 'Traditional' family values?"
C: "No, none of those..."
M: "Oh, so it's not really conservatism that's being silenced then... just lies and hate."