Monero is much less secure. Given the best CPU on the market you can get around 0.5KH/J. The total hashrate of monero is 2.32GH. So an attacker would need 4.0x10^11J of energy per day. With a cost of energy of $0.05 per KWH that comes out to $25k per day to 51% attack monero. This is a rough estimate but look at https://bitinfocharts.com/monero/ you'll see total miner reward is around $70K so not far off.

Since its pretty easy for anyone to rent CPU power given the large number of data centers in the world the only cost would be power plus a premium to the data center so at worst case scenario monero would only cost 50k/per day to shut down. This is easily done by wealth individuals or a small countries. And given how much centralized powers hate monero I wouldn't be surprised if the US or EU did this to stop terrorist organization or what ever they dem an enemy.