Personally, I run no anti-virus or security software, no cleaning apps, never install third-party drive vendor software (e.g. WD), and only run malwarebytes once, and then from its help menu, uninstall it. I do so, because its real-time RTDaemon sets a nice value of -20, the highest priority of all processes, and that has to take a bite out of responsiveness. You may find that ClamXav and Little Snitch may also tamper with the nice value and are having adverse impact on your interactive (e.g. application launch) performance.
Considering how resource hungry Monterey, and Pages are, that 3 - 4 second lag on a 2015 Mac running Monterey on an Apple SSD of that era is not unreasonable. You just don't want to launch Pages immediately after boot and run into the normal System housekeeping headwinds of Spotlight, Software Update, etc.
I am running Monterey 12.4 and Pages 12.1 on the following hardware:
- 2020 27-inch iMac 3.8Ghz 8/16 Core i7, 1TB Apple SSD, 40GB RAM, and Radeon Pro 5500 XT w/8GB
- 2021 16-inch MBP M1 Pro, 1TB Apple SSD, 32GB RAM, and standard GPU
On the iMac, with no other user applications running Pages alone reaches the Template chooser in about 1s. Opening a 180-page text document takes about 3s. On the M1 MBP, Pages reaches the Template chooser in 1s, and opening that same 180-page document about 2s.
From the Terminal, you can review your current pid, priority, nice, and associated command values using:
ps -h -c -e -o pid,pri,nice,command | awk '!/PID|^$/ {print | "sort -nrk3"}' | more
where a reverse numeric sort is happening on the nice column of numbers. I am removing the n-tuple occurrences of process status headings and blank lines.
I trust my own system security to common sense, my router settings, and Monterey's built-in security. I have no issues for those reasons. I have been using Macs since the Mac Classic was introduced in 1984, in corporate and personal usage, and have only encountered 1 virus on a Powerbook 540C when a colleague shared an infected Word document.