Absolutely, it's driving me mad (no pun intended) seeing the garda checkpoints doing nothing only causing delays. I've always just been waved on. It's not the people in cars in the middle of the day spreading it.
Enforce isolation. Give isolation address and then it will be spot checked (Garda call to the door). Fines if breaching it.
Garda to drive around at night/answer calls to where house parties are.
Spot check businesses to ensure they are compliant, businesses with customers and without customers. Most are. Check ventilation, cleaning, social distancing etc. Frequent checks on known offenders and close them down (e.g. pubs that are known to have lockins)
Allow things that are low risk. They lost me when they tried to stop parents watching their 8 year old play gaa (they rowed back a bit on that). So instead parents went to a cafe, which is much higher risk.
Invest in public health department and contact tracing instead of garda check points.