Not saying maintenance isn't a problem, it probably is. It's a problem everywhere in Europe. Have you seen train service in England, Germany or Sweden? Absolutely terrible, compared to just two decades ago.
But under-maintenance causes trains to stand still and be late. It does not cause them to crash.
Crashes are caused by running at speeds higher than the (under-maintained) rail can support, or (against all rules and every regulation) no cap on speed when the signalling system is down.
The latter can not be solved with more money and resources. It is a culture problem. Rules can not routinely be disregarded for arbitrary reasons, especially not when they are completely in line with common sense.
The rumor is that staff is being pushed to restore service as fast as possible after a problem is "solved". EU push for green transport and privatization means lines were opened to competition, increasing the number of trains compared to some decades ago when only one operator used them with less trains than it does now. IIRC currently the lines have two operators (3 in some places?), meaning that traffic more than doubled. Those in power do not want the service to have more delays. And instead of updating and maintaining the infrastructure, Adif stresses it even more, both in the technical and personal fronts. Thus the accidents. But nobody at the top resigns, blame low level scapegoats instead.
The Iryo train was stopped and unable to restart, because it's safety system did not allow that until the signalling issue was corrected. The AVE was commanded to move again like normal (200 Km/h or more). When the Iryo reported to be stuck, all the trains in the line should have been notified to stop once more, or go at line-of-sight speeds (40 Km/h). Both options are bad for delays. Current news is that five minutes after the Iryo call, the AVE rammed its back at 160-200 Km/h.
CEO of Iryo company complained 3 weeks ago about LZB being problematic, their trains taking a long time to recover connection. Safe but old, he said. It should have been replaced by ERTMS by 2024-2026.
> When the Iryo reported to be stuck, all the trains in the line should have been notified to stop once more
That would have meant that the dispatcher would have been aware that they already ordered a collision before. If a train stops no accident will happen, unless it could have happened regardless. Yes, such a decision would have prevented the accident or lessened it's impact, but the absence of it has not caused it. The error was already done before.
> they already ordered a collision before
What do you mean? "Everyone crash now"? Makes no sense. "Tried to solve"? There was no collision before.
The situation seems to be that they stopped the trains due to a problem somewhere. When they thought it was solved, they commanded all of them to move again. And when one reported to be unable to do so, they failed to stop those that were around it. Or that is what the leaked conversations suggest. Do not discard this was tactical leaks to blame a scapegoat. The newer system should be running.
I say around, because news mention that a third train could have crashed into the wreckage of the other two. It was moving in the other direction, towards Madrid. Luckly it stopped when the electricity failed. It would have been like the accident early this year, when a train hit other that just had a derailment.