Read receipts are an RCS feature. MMS and SMS don't allow for this. Read receipts work on iMessage due to how similar it is to another semi-open relay system like BBM.
I don't know if it's still a thing, but most carriers like Verizon or ATT offer you the ability to rent a phone or borrow one from a store for 48 hours or so to get an idea if you want it. I could be thinking of an ancient program so don't take my word for it.
FWIW, the update issue isn't on Samsung.
Android phones typically use Qualcomm SoC. In some territories, where Samsung phones use Exynos processors, they can get updates years after the phone ships. Qualcomm typically does not supply new driver sets to manufacturers past 2-3 years even if the handset manufacturers ask for them. Repeatedly.
Once Qualcomm supplies drivers for a new version of Android, the manufacturer develops their top layer of software, tests it and ships it to carriers. It's up to the carriers to do the last mile work. Verizon was one of the first carriers to ship Pie in mid January if not earlier. TMO just released Pie after placing a hold on the update a half day into shipping it out.
Android Z could come out in August. Samsung could have it done by October or November. It'll take carriers anywhere from 3 months to 9 months to ship something out. Qualcomm needs to be taken out of the equation or have an externally manufactured problem to cripple their bottom line and allow other chip makers to swoop in and take up their place.
In the case of Chinese handset makers. Their prices are low now, but they'll go up. OnePlus has shown a year over year price increase each generation now. The first OnePlus phone was under $290 using a flagship grade Snapdragon SoC. Current one costs $550, and it's rumored the One Plus 7 will cost around $700.
Don't expect companies like Xiaomi to not raise their prices year after year, too.