Sparkplugs, batteries, headlights. These are all thing that will only be replaced ever 4-5 years. They should also be planned to be replaced before they fail per the owners manual. Why would anything that needs to be replaced that seldom ever be a consideration for fast replacement design effort.
By the way. I have replaced the rear bank spark plugs on a 98 Buick Le Sabre (3800 series) a few times. Nothing needed to be removed and it wasn't too bad. Not as bad as doing a 99 Dodge Caravan's rear plugs. The lower intake gasket sucked on my brother's 97 3100 V6 Skylark.
2011 Smokin Buck Ferton 155
2013 Flow NX2-SE
2013 Flow Hylite boa
Burton Stagger pants/jacket