If someone called 998, then yes, please listen to them. Listen attentively, validate their feelings, but soothe and comfort and reassure them. There are systematic ways to do this and they can get results.
But never ever call 998. Beware if someone offers to do so. Your hospital incarceration will be more traumatic, damaging, and expensive than any other alternative.
Get help before it gets to that point. Seek out good therapists and support groups when you're sane and calm, and stick to your treatment. Do it in-person, face-to-face. There is no substitute.
This is weak enough that it will happen many times for people who are not in a significant risk, but for whom such an intervention can be seriously detrimental to their life. Note that suicidal thoughts are most of the time just thoughts and not acted upon.
If nothing else, it should be made clear to the person calling what risks they are taking. Many people might believe that they have confidentiality and that they can talk freely without risk of consequence.
Some people who call a suicide prevention hotline will go on to kill themself. That by itself is not evidence of a flaw in the hotline or its policies.
Many times ordinary people have suicidal thoughts and don't carry out it at all. Subjecting those people to coercive treatments would be extremely harmful as doing so will further traumatize them. And it's also an affront to individual liberty, including the freedom to have negative thoughts. Sometimes such thoughts, if not interfered with by a meddling "nanny state", are an opportunity for growth and recovery.
And this hotline can also be used as yet another means of coercive control by a partner with Narcissistic Personality Disorder, or other personality disorders. Where the partner can threaten to report the victim as suicidal or mentally unstable. Yes that happens, and it's surprisingly common. That's why here in the UK we passed laws against coercive control.