There will come a point when the Army is not purchasing ACOG's anymore and then the trijicon people will probably scramble to makes something better that the Army might buy.
If that doesn't pan out they will. I can't see an optic running more than 20 years esspecially today. They lack one terribly obvious feature-- variable magnification with a low 1 power setting.
Think of it-- the Unertle 8power target scopes with external ajustments were used for like 25years, the redfields 10-15, the Army used Leatherwoods for maybe 25years, the Army used Colt/Realist 4power BDC scopes for maybe 10 years.
The point is that there is no Browning 1911 of optics at this point The Acog has run ten years and will probably run ten more though I would expect contracts to drop off soon. Already if US Optics could move production to a larger facility and lower the price slightly of a SN4 1-4 power with the JP1 reticle they would have strong ACOG competition. Fiber optic ACOGs aren't night vision compatible, the SN4 is. The std Acog can't do reflex work-- the SN4 can
lower price-- I don't know if you want to wait 15 years for your ACOG.