Have you tried doing some research? No need to look at gigabits. Look at cost per unit of bandwidth. It might change your point of view.
It's gone down, considerably. Family plans are nearly 50% less in many cases than they used to be.
Individual plans -- circa 2005ish... 450 minutes of calling ($40), plus unlimited data ($30), plus unlimited texting ($10) used to run 80/mo per line - a completely flat cost to today.
Family plans - Family of 4 circa 2005ish... these used pooled minutes, putting you to the 2100 minute plans ($110), plus unlimited data charged individually (30x4 = $120), plus unlimited texting charged individually (10x4 = $40). That's 270/mo. T-Mobile today is 40 or 43 per line at 4 lines, depending on regular or Plus... max 170/mo. AT&T has 3 tiers, 35 per line (140/mo), 40 per line (160/mo) or 48 per line... so max 190/mo. Verizon, classically the most expensive carrier, also has 3 tiers... 35, 45, 55 per line... max 220.
In all cases it's cheaper than old family plans. Except now minutes and texts are rolled in to the overall cost.
So... flat for single lines at a comparable service level... far cheaper for family plans.
Let's not even back it up into the 90s or 80s... before consolidation began. It'll just get silly when we start comparing several thousand dollar cell phone bills to what they are now.
Consolidation lowers prices... it's called Economies of Scale.