Dual-SIM phones were the hot shit for years when phones were beginning to take off. I remember some weird adapters that cycled through SIMs when the phone was restarted and all kinds of other hacks.
I mean, all top end Samsungs are proper dual SIM phones still(they take two physical Sims). #1 reason why I'm still buying them and not any other brand. iPhones also support dual SIM but only with one physical card and one eSIM.
Also not top end ones. Example, the Samsung A40, a mid range sub 300 EUR phone. There is plenty of space for SIMs in nowadays' ridiculously sized phones.
You don't even need Dual-SIM phones, contemporary SIM can contain various numbers/administrations. Both with and without hackery involved. It's just that the carriers don't want it / block it.
This is also why many of them outright refuse to sell phones with dual SIM capability.
> This is also why many of them outright refuse to sell phones with dual SIM capability.
At least here in the EU, carriers don't follow typical US customs any more... a series of court verdicts following the 2005 commerce directive has all but eliminated SIM locking and other hostile practices by carriers, the worst you (unfortunately) still get is bloatware.